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Practical Lessons 



ON 



The Lever Escapement 

Its Tests, Errors 

Their Detection and Correction 

By T. J. WILKINSON 

Author of "Practical Studies in 'the Lever Escapement," 
"Train, Wheel and Pinion Problems"; "Length of 
Lever and Roller Jewel Radius," etc., etc. 



TECHNICAL PUBLISHING COMPANY 

2258 North Front Street 

Philadelphia, Penna. 



Copyright, 1916, hy T. J. Wilkinson 



TS5-4S- 
INTRODUCTION 



WS 



This book on the Lever Escapement is sent forth with the 
hope that students in horology, the young and the advanced, will 
find pleasure and profit in using it. 

A part of this volume recently appeared in the columns of the 
Jewelers' Circular, to the Editors of which the author desires to 
return thanks for favors extended. 

The system outlined and described in the Lessons has had a 
thorough and successful test, not only with beginners, but with 
workmen of wide experience, and will be found adapted to the 
needs of both. 

Upon the completion of our last escapement series, many 
written commendations from unknown readers were received. 
The following is an extract from one of these letters: 

"I am a practical watchmaker for the past twenty years, and, 
although considered a skilled workman, I have profited more from 
your recent publication in the Jewelers' Circular than from any 
amount of practice." 

This plain statement should spur others to add to the knowl- 
edge they now possess, increased skill being an invaluable asset. 

To tell a man you know the road to "Wheeltown" and then 
admit you are not capable of directing him on his way, is and 
has been the position of many as regards the Lever Escapement 
and its tests. A want of nomenclature has been largely respon- 
sible for this. The writer therefore at different times coined 
descriptive terms, such as "Angular Test," "Corner Test," "Cor- 
ner Safety Test," etc. The term "Tripping," an old one in horol- 
ogy, we have divided up into three parts, giving to each a def- 
inite meaning, namely, "Corner Trip," "Guard Trip," "Curve 
Trip." The adoption of exact expressions renders explanation and 
instruction more profitable for all. 

We plead guilty to repetition in the Lessons. Some one has 
wisely remarked, "Reiteration is education," and our experience 
has proven its truthfulness. No further comment on this score 
is necessary. 

The methods outlined in the book provide students with an 
undoubted short cut to Escapement knowledge, both practical 
and theoretical. Previously, command over the Escapement and 
its problems was ^acrquired by years of bench practice and experi- 
ment, which, because undirected, often failed of its purpose or 
lead to erroneous 'decisions. Such drawbacks the book's teachings 
avert. If the reader will study the Lessons, work out the solu- 
tion of each Test Lesson and make use of the Questions, quickly 
his work will show a decided improvement, alike pleasing and 
satisfactory to all. ' 

Philadelphia, 1916. .ninic T.J.Wilkinson. 

JUL 18 I9lb j^ /V^l 



5GI.A433762 



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LESSON 



ADVICE— PRACTICE 



1. We shall devote this our opening lesson to two things — 
advising students how to gain most profit from this study of the 
lever escapement and to describing in brief elementary terms such 
horological words as are necessary to our subject. Students are 
asked to study each item as a link in the chain of escapement 
knowledge. As you read through the lessons mark, learn and 
thoroughly digest every paragraph. In a work of this class repe- 
tition is necessary. Repetition is a good method of teaching. It 
impresses facts important to be known and remembered; hence 
we have not hesitated to employ it. 

Systematic study and work will save young watchmakers 
years of unsatisfactory experience at the bench. The results to 
be obtained are, therefore, worthy of the effort. A certain amount 
of theory is necessary to understand the basis of escapement form 
and construction. The extent of theory in the following lessons 
is limited to such as can be practically made use of. The escape- 
ment tests are all practical; you must be acquainted with them 
if you desire to do your work well and quickly. In connection 
with them we advise experimental work; prove all things men- 
tioned in the following lessons; but above all, see that you under- 
stand each and every move. Depart from the ways of the average 
watchmaker, who when asked to explain various features of the 
escapement or errors connected with same replies by saying, 
"I know, but I can't explain"; yet the same man will give you a 
clear, intelligent description as to how he cleans a watch. He 
knows the latter, but the escapement is somewhat of a muddle and 
puzzle to him. 

The student who will carefully study the following lessons 
will know and will be able to explain the whys and wherefores of 
escapement problems such as he encounters every day at the 
bench. 

REQUIREMENTS FOR PRACTICE 

2. To combine study with practical work students should pro- 
vide themselves with a 16-size three-quarter plate, or else a bridge 
movement of either Waltham, Elgin, Illinois, Rockford or Hamil- 
ton type. The 16-size three-quarter plate movement is favored be- 
cause the parts are fairly visible; besides, examinations and tests 
are more easily conducted, the parts being more accessible. For 



2 

experimental purposes it is also necessary that students obtain 
several old movements, including some New York Standards. For 
the latter an extra supply of levers and table rollers is desirable. 
As the movements named possess composition levers, they are well 
adapted for research escapement work. Students when sufficiently 
advanced should make a point of examining all escapements. By 
this means they become familiar with the routine of escapement 
testing. 

In the experimental work various errors should be created; 
much can be learned along this line. For instance, by bending the 
lever we can throw the escapement "out of angle," or we can 
create this defect by making the drop lock on one pallet stone 
greater or less in amount than that found on the opposite 
pallet. 

Composition levers are easily altered, either lengthened or 
shortened, as desired. The result of changing the lever's length 
can be shown and detected by the tests. Therefore, when experi- 
menting we can, by employing the tests, determine how and in 
what manner an escapement is deranged and what alterations are 
necessary to restore the escapement to a normal condition. 

Experimental research work will be found the best and surest 
road toward a complete mastery of the problems of the lever es- 
capement. In a practical way — namely, at the bench — we hope 
our readers will apply the methods about to be set forth. 



LESSON 2 



DEFINITIONS 



BALANCE 

3. Balance, — The vibratory wheel of a watch, which, in con- 
junction with the hairspring, controls the progress of the hands. 

4. Balance Arc. — For definition of balance arc see No. 106. 

5. Balance Arc of Yidration. — See No. 108. 

6. Balance, Supplementary Arc. — See No. 107. 

7. Balance Staff. — The axis of the balance. 

8. Balance Spring. — The fine coiled spring attached by a collet 
to the balance staff. Frequently it is termed the hairspring. 
This spring assists the balance to vibrate. 

9. Balance Wheel. — The escape wheel of a verge watch. It is 
incorrect to employ the term "balance wheel" to express the bal- 
ance as used in the lever and other watches. 

BANKING 

10. Banking. — In a lever watch the term "banking" implies 
that the roller jewel, due to an excessive vibration of the balance, 
strikes on the outside of the lever horn. This error might result 
from using a mainspring of too great a strength. 

11. Banking Pins. — In modern American watches the banking 
pins placed on each side of the lever are eccentric extensions from 
the screws. This method of construction allows of a great deal of 
latitude in controlling the amount of lock and the lever's motion. 

12. Bank. — A shortening of the term "banking pin." 

13. Banked to Drop. — ^An escapement term implying that slide 
or second lock has been eliminated. To bank an escapement to 
drop, it is necessary to close in the banking pins to such an extent 
that drop lock only is present. 

14. Banked to Drop, Elgin Type. — ^When an escapement of the 
Elgin type is banked to drop, a slight freedom exists between 
guard point and edge of table (guard freedom) ; also between slot 
corners and roller jewels (corner freedom). 

15. Banked to Drop, South Bend Type. — When an escapement 
of the South Bend type is banked to drop, no freedom is found 
either of the guard point with edge of table or of the roller jewel 
with the slot corners. 



16. Banked for Slide. — This expression refers to the presence 
in an escapement of the slide or increase of the lock which (when 
the bankings are open) follows drop lock. 

DROP AND SHAKE 

17. DroiJ. — ^When a tooth of the escape wheel is discharged 
from either pallet stone the escape wheel is immediately released 
from all contact. The wheel's motion is then entirely free. This 
free flight of the wheel, termed "drop," ceases the moment another 
tooth meets the locking face of an intercepting pallet jewel. 
Drop is also defined as the space through which an escape wheel 
moves without doing any work. 

18. Inside Drop. — Is that space through which the escape 
wheel moves whenever a tooth leaves the releasing corner of the 
entering pallet jewel. Inside drop ceases the moment another 
tooth strikes the locking face of the exit pallet. 

19. Outside Drop. — Is that space through which the escape 
wheel moves when a tooth becomes disengaged from the releasing 
corner of the exit pallet. Outside drop ceases the moment another 
tooth meets the locking face of the entering pallet. 

20. Shake. — The term "shake" implies that position of the 
pallet jewels with the adjacent teeth of the escape wheel where 
least freedom of parts is found to exist. The following is more 
explanatory: 

21. Inside Shake. — The position of least freedom of the escape 
wheel teeth embraced detween the pallet jewels at the moment of 
unlocking. A practical observation by the student will make this 
clear. Bring the tooth at rest on the locking face of the exit or 
discharging pallet down to the pallet's lowest locking corner; then 
note the space separating the back of the entering pallet from 
the heel of the tooth just behind it. The space seen separating 
the point of the tooth from the back of the entering pallet repre- 
sents the amount of inside shake. When in this position the 
parts have least freedom. 

22. Outside Shake. — This term refers to that position of the 
escape wheel teeth outside the pallet jewels where least freedom 
exists. Practical demonstration will make this clear. To discover 
the amount of outside shake bring the tooth of the escape wheel 
found resting on the locking face of the entering pallet jewel 
down to the lowest locking corner of this stone. Hold the parts 
in this position and notice the space separating the back of the 
exit pallet from the heel of the tooth just behind it. The space 
observed represents the outside shake and shows the least free- 
dom of the parts, which occurs always at the moment of 
unlocking. 

DRAW 

23. Draw. — The force which holds the lever against its bank. 
Draw is chiefly the result of the angle given to the pallet jewel's 



locking face. The force of draw is also helped by the angle on 
the locking faces of the teeth of the escape wheel. It is advisable 
for students to learn and compare the terms "draw," "run" and 
"slide." 

24. Draw Lock. — See slide. 

ESCAPEMENT 

25. Escapement. — That part of a lever watch which changes 
the circular force of the escape wheel into the vibratory motion 
of the balance. 

26. Single Roller Escapement. — A single roller escapement, 
as the name implies, possesses but one table roller. The office 
of this roller is as follows: First, to carry the roller jewel; 
second, its periphery or edge is a part of the safety action; third, 
the crescent or passing hollow provides space for the free passage 
of the guard point. 

27. Double Roller Escapement. — Escapements of this type 
possess two rollers. The larger, or impulse table, carries the 
roller jewel. The smaller, or safety roller, is an important factor 
in the safety action. It also contains the crescent or passing hollow. 

28. Right-Angled Escapement. — In a right-angle escapement 
we find the line of centers of pallet and balance crossed at right 
angles by the line of the escape wheel. 

29. Straight-Line Escapement. — A straight-line escapement 
is one wherein we find the pallets, lever and balance all planted 
in a straight line. 

ESCAPE WHEEL 

30. Club Tooth Wheel. — This term describes the shape of 
an escape wheel tooth as used in American watches. 

31. Ratchet Tooth Wheel. — A wedge-shaped form of tooth 
used in escape wheels of English-made watches. 

32. Lift on Tooth. — The slant on the upper face of a club 
tooth. In Fig. 1 the line A B embraces "the lift." 




33. Pitch of Tooth's Locking Face. — The angle found on the 
back of each tooth. (See Fig. 1, B to C.) 



6 

34. Tooth's Impulse Face. — See "Lift on Tooth." 

35. Heel of Tooth. — In the illustration Fig. 1 the point A is 
the heel. 

36. Toe of Tooth. — The point B (Fig. 1) is the toe of the 
tooth. 

LOCK 

37. Locking. — The overlapping contact of an escape wheel 
tooth on a pallet jewel's locking face. 

38. Drop Lock. — That point of contact of a tooth of the 
escape wheel as it drops onto the pallet jewel's locking face. 
Drop lock is also termed the first, or primary, lock. 

39. Drop Lock, Elgin type. — Of the total lock in an Elgin 
type of escapement, about two-thirds represents drop or first lock, 

40. Drop Lock, South Bend Type. — One-half of the total lock 
in this type of escapement will equal the amount of drop lock. 

41. Slide or Slide Lock. — This expression refers to the fur- 
ther increase of the lock following the drop lock. Slide lock is 
variously known as draw lock, second lock or simply as slide. 

42. Slide, Elgin Type. — About one-third of the total lock in 
an Elgin type of escapement should be slide. 

43. Slide, South Bend Type. — One-half of the total lock in an 
escapement of this type will be slide or second lock. 

44. Remaining or Safety Lock. — The amount of lock of the 
tooth on the pallet jewel's locking face which remains when the 
safety tests are used. (See corner safety and guard safety tests.) 

45. Total Lock. — A term including both drop and slide lock. 
Total lock is therefore the sum of both. 

OVERBANKING 

46. Overdanked. — The term "overbanked" expresses the fact 
that the roller jewel has come to rest against the outside of the 
lever horns. Whenever, owing to some defect, the lever passes 
in an irregular manner over to the opposite bank, the roller jewel 
then strikes the outside of the lever and the watch is said to 
be overbanked. 

LEVER 

47. Lever. — The fiat metal bar which conveys and transmits 
motion to the balance. To the lever bar is attached the pallet 
arms. The end of the lever associated with the roller jewel is 
termed the fork. 

48. Acting Length of Lever. — The distance from the pallet 
center to the slot corners represents the lever's acting length. 

49. Lever Horns. — The circular sides of the fork leading into 
the slot. 

50. Lever Slot or Notch. — The slot cut into the lever bar, 
centrally located below and between the lever horns. 



51. Forlc. — A term including both slot and horns of lever. 

52. Run of Lever. — The continued motion of the lever toward 
its bank which takes place when slide or second lock is present. 
The amount of run always equals the amount of slide. 

PALLETS 

53. The Pallets. — The metal body attached to or a part of 
the lever. This includes the pallet arms and jewels. Together 
the pallet jewels and metal body comprise the pallets. By means 
of these parts the escape wheel transfers its energy to the lever 
and balance. 

54. Pallet Arms. — The metal body which contains the pallet 
jewels. 

55. Pallet Jewels. — The jewels or stones inserted in the pallet 
arms for the purpose of receiving and transmitting the energy 
delivered by the escape wheel. 

56. Pallet Staff. — The axis of the pallets and to which the 
pallet arms and lever are attached. 

57. Entering or Receiving Pallet. — That pallet jewel over 
which a tooth of the escape wheel slides in order to enter between 
the pallet stones. 

58. Exit or Discharging Pallet. — That pallet stone which an 
escape wheel tooth slides over in order to make its exit outside 
the pallet jewels. 

59. Pallet's Impulse Face or Plane. — The lower surface of a 
pallet jewel upon which the escape wheel teeth act. 

60. Lift on Pallet. — The pitch or slant of the impulse plane. 

61. Pallet's Locking Face. — That portion of a pallet jewel 
upon which a tooth of the escape wheel drops and locks. 

62. Releasing Corner of Pallet. — That point on a pallet stone's 
impulse face where the tooth is released from contact with the 
pallet. 

63. Pallets Circular. — ^A type of pallet so constructed that 
(central) points located on each pallet jewel's impulse face, 
midway between the entering and releasing corner, are exactly 
at the same distance from the pallet center. This arrangement, of 
course, places the locking faces at an unequal distance from the 
center of the pallet. Circular pallets are used in American-made 
watches. 

64. Pallets Equidistant. — Pallets that have their locking faces 
equally distant from the pallet center are known as equidistant 
pallets. This form is found only in foreign-made watches of 
very high grade. 

ROLLER JEWEL 

65. Roller Jewel. — The long, thin cylindrical-shaped jewel 
inserted in the table roller; also called the "jewel pin," the 
"impulse pin." 



66. Roller Jewel Radius. — The distance from the center of 
the roller to the face of the roller jewel. 

SAFETY ACTION 

67. The Safety Actions. — In a single roller escapement the 
safety actions include the following: Guard pin, edge of roller, 
roller jewel, corners of lever slot and a small portion of the 
horns close to the slot corners; and we may include the drop 
locks. In a double roller escapement the parts are the guard 
finger, the roller jewel, the lever horns, the slot corners, safety 
roller and the drop locks. 

68. Guard Pin. — The upright pin inserted in the lever bar 
just behind the slot. The term "guard pin" applies to single 
roller escapements. 

69. Guard Finger. — The pin extending from the lever bar of 
a double roller escapement and pointing toward the safety roller. 

70. Guard Point. — As used in these lessons, this term ex- 
presses either the guard pin or the guard finger. 

71. Guard Radius. — The distance from the center of the pallet 
staff to the outside of the guard point. 

72. Guard Test and Guard Safety Test. — For definitions con- 
sult Nos. 82 and 85. 

ROLLERS 

73. Tal)le Roller or Impulse Roller. — The circular disc 
attached to the balance staff and into which the roller jewel is 
inserted. In single roller escapements the crescent or passing 
hollow is cut into the edge of the roller. 

74. Safety Roller or Safety Tahle. — The smaller sized disc 
found in double roller escapements. In its edge is located the 
deep, wide cutting called the crescent or passing hollow. 

75. Crescent or Passing Hollow. — The circular cut or bight 
formed in the edge of a roller. Its purpose is to provide for 
the necessary intersection of the guard point during the latter's 
excursion from bank to bank. Width and depth are important 
features of the crescent. 

76. Diameter of Roller. — The diameter of a roller is a line 
drawn from any point on its edge to a point directly opposite, 
but the line so drawn must pass through the centre of the roller. 

TESTS AND TEST TERMS 

77. Angular Test. — ^A test used to show the relationship 
existing between the amount of drop lock and the lever acting 
length. Assuming the drop locks as correct, the angular test 
will show if the lever's length is correct, long or short. This 
test is also employed to show if an escapement is "in angle" 
or "out of angle." 



9 

78. Corner Test. — A test used to discover the relation of the 
roller jewel with the slot corners of the lever. It is most accurate 
when made under banked-to-drop conditions. 

79. Corner Freedom. — The freedom found by the corner test 
between the roller jewel and the slot corners. 

80. Corner Safety Test. — That subdivision of the corner test 
which shows if the remaining or safety lock is present or absent. 

81. Curve Test. — The test used to discover if the curves of 
the lever horns are correctly related to the roller jewel. It is 
mostly applied to double roller escapements. 

82. Curve Safety Test. — A subdivision of the curve test 
whereby we learn about the condition of the remaining or safety 
lock. 

83. Guard Test. — This test is employed to determine the posi- 
tion of the guard point with reference to the edge of the roller. 

84. Guard Freedom. — The freedom found between the guard 
point and edge of roller. 

85. Guard Safety Test. — ^A subdivision of the guard test 
which enables us to learn about the condition of the remaining 
or safety lock. 

TRIPPING 

86. Tripping. — Tripping is the irregular act of an escape 
wheel tooth entering on to a pallet jewel's impulse face owing 
to a fault in the safety action. When the safety tests are em- 
ployed tripping is shown by the absence of a safety or remain- 
ing lock. 

87. Corner Trip. — The want of a remaining or safety lock 
discovered by means of the Corner Safety Test. 

88. Curve Trip. — A lack of safety lock developing when the 
Curve Safety Test is applied. 

89. Guard Trip. — An absence of safety lock found by means 
of the Guard Safety Test. 

LINE OF CENTER— OUT OF ANGLE— ADJUSTING LET-OFF 

90. Line of Centers. — The line of centers in the lever escape- 
ment is a line drawn from the center of the pallet hole jewel 
to the center of the balance hole jewel. The lever as it travels 
from bank to bank moves an equal distance on each side of 
this line. 

91. Out of angle. — ^When an escapement is out of angle and 
the watch Itanked to drop, the lever, as judged by the line of 
centers, moves an unequal distance on each side of this line in 
order to reach its bank. The guard point indicates an escape- 
ment as out of angle when it has greater freedom on one side 
of the roller than on the opposite side. The roller jewel shows 
the escapement as out of angle by an inequality of freedom with 



10 

each slot corner. Out of angle is corrected by altering the pallet 
stones or bending the lever, or perhaps both. To correctly decide 
if an escapement is out of angle it must te banked to drop. 

92. Let-off Adjusting. — Adjusting the "let off" is a factory 
expression denoting the escapement is out of angle. It implies 
that one or both pallet stones need altering or the lever requires 
bending to provide the guard point with an equal amount of 
shake on each side of the roller and to give the roller jewel an 
equal amount of freedom with each slot corner. As adjustments 
are made with the escapement banked to drop, the final result 
is an equal motion of the lever on each side of its line of centers. 



11 



LESSON 3 



ANGLES— CIRCLES— DEGREES 



NECESSARY KNOWLEDGE 

93. Every student aspiring to become master of the principles 
of escapement construction must at least possess a practical 
working knowledge of angles, degrees, etc. A knowledge of 
escapement drafting is also desirable. As a majority of students 
lack this necessary instruction, we have in this and succeeding 
chapters enumerated such points as have a direct and practical 
bearing on our subject. 

ANGLES 

94. An angle is the opening between two lines which meet 
at a point. The meeting place is termed the vertex; the lines 
defining the angle are called its sides. When an angle stands 
alone it can be named by the letter placed at the meeting point of 
the lines. For instance, we refer to angle B (Fig. 2). Should two 




Fig. 2 



Fig. 3 



or more angles meet at a common center they are named by three 
letters, as A B C or C B D (Fig. 3). Angles are spoken of as so 
many degrees in width. The greater the divergence of the lines 
of an angle the greater the number of degrees contained by that 
angle. The size of an angle is measured by the extent of its 



12 

opening relative to the 360 degrees in a circle. We shall therefore 
discuss angles and their degrees in our discussion of circles. 

CIRCLES 

95. A circle is a plane figure bounded by a curved line, called 

its circumference. All lines drawn from the center of the circle 

to its circumference are equal in length. The lines A E, E C, 

E D and E B (Fig. 4) are equal. The diameter of a circle is any 




Fig. 4 

straight line drawn from circumference to circumference and 
passing through the circle's center. The lines A D and K B are 
diameters of the circle (Fig. 4). 

RADIUS 

96. The radius of a circle is any straight line draivn from the 
center to the circumference. The lines E C, E B, etc., are radii 
of the circle (Fig. 4). ("Radius" is the singular; "radii" the 
plural.) 

ARC 

97. An arc of a circle may be any portion of the circle's 
circumference. Thus A to C (Fig. 4) is an arc. 

TANGENT 

98. A tangent to a circle is a straight line which touches the 
circle at only one point. The tangent is always perpendicular to 
the radius drawn to that point. In Fig. 4 the line T L is tangent 
to the circle at the point C and the radius E C is the tangent's 
perpendicular; consequently the angles T C E and L C E contain 
90 degrees each. 

SEMICIRCLE 

99. A semicircle, as the name implies, is one-half of a circle; 
every semicircle contains 180 degrees. 



13 

QUADRANT 

100. A quadrant is the one-fourth part of a circle, and contains 
90 degrees. 

RULES APPLYING TO CIRCLES 

101. Radius equals one-half the diameter. 
Radius multiplied by 2 equals one diameter. 

Radius multiplied by 2 by 3.1416 equals circumference. 
Diameter multiplied by 3.1416 equals circumference. 

DEGREES 

102. The circumference of every circle is supposed to be 
divided into 360 equal parts; each division or part is termed a 
degree. The degree is again subdivided into minutes; each degree 
contains 60 minutes. 

TABLE OF SIGNS 

103. Three hundred and sixty degrees is equal to one circle. 
Sixty minutes is equal to one degree. 

Degree sign (°) used for degrees. 
Minute sign (') used for minutes. 

LENGTH OP ONE DEGREE 

104. The length of one degree changes with the size of the 
circle of which it is the 1/360 part. The length of one degree on 
the earth surface is about 60 geographical miles. The size of one 
degree on the circumference of a circle measuring 360 feet would 
equal one foot (360 -^ 360 = 1). Prom the foregoing statements 
we learn that the size of one degree is a varying factor altogether 
dependent on the size of the circle. The size of a degree in watch- 
work likwise varies with the size of the circle of which it is the 
1-360 part. Por instance, two degrees of lock in an 18-size escape- 
ment will measure more than two degrees of lock in an 0-size 
watch. Again, two degrees of lock measures more on the enter- 
ing pallet of any American watch than two degrees do on the 
exit pallet of the same watch, because, being circular pallets, 
their respective locking faces are placed at different distances 
from the pallet center. This the student can demonstrate by 
measuring the distance from center of pallet staff to lowest lock- 
ing corner of each pallet jewel as directed in item No. 180. 

PROTRACTORS OR ANGLE MEASURES 

105. Students can quickly advance their practical knowledge 
of angles and degrees by becoming acquainted with an instrument 
for the measurement of angles called a protractor, as illustrated 



14 

in Fig. 5. Suppose we wish to measure the size of angle B (Fig. 
2 ) ; we can do so by placing the center of the protractor at B, 
its 90-degree mark extending along the line B A. When so placed 




Fig. 5 



it is an easy matter to count off the degrees enclosed by A B C as 
an angle of 30 degrees. It is not a difficult matter to become 
familiar with the various methods of using the protractor. Cheap 
protractors are usually unreliable, and the student who intends 
to pursue a thorough course in escapement drafting is advised to 
purchase a reliable instrument. 



15 



LESSON 4 



BALANCE ARC— SUPPLEMENTARY ARC— ARC 
OF VIBRATION 



106. Balance Arc. — The definition of an arc, as before given, 
is any part of a circle's circumference. The balance arc is that 
part of the arc of vibration during which the roller jewel is in 
contact with the lever. The extent of this balance arc varies; 
usually it is around 30 to 40 degrees, smaller arcs being employed 
in double than in single roller escapements. The extent of the 
balance arc is, of course, measured from the balance center. 

107. Supplementary Arc. — The supplementary arc represents 
that portion of the arc of vibration of the balance during whicla 
the roller jewel is detached from the lever ; we might also because 
of its detachment, term it the "free arc." 

108. Arc of Vihration. — The arc of vibration equals the sum 
of supplementary arc plus the balance arc. Accordingly the arc 
of vibration represents the full swing or motion of the balance. 

109. Motion of Balance. — What constitutes a good motion is 
a question of dispute. Indeed, many watchmakers have but little 
conception of what the proper motion of a watch should be. To 
determine the arc of vibration takes a combined trained eye and 
mind; these every watchmaker should cultivate. It has been 
demonstrated that when a balance gives one and one-eighth to 
one and one-quarter turns it neutralizes slight inaccuracies in the 
poise of the balance. One and one-eighth turns means an arc of 
vibration of 405 degrees; one and one-quarter turns expresses an 
arc of 450 degrees; one and one-half turns equals a vibratory arc 
of 540 degrees. Regarding the question of a good motion, the 
man at the bench usually prefers an arc of 450 to 540 degrees. The 
vibratory arc, however, should not exceed 540 degrees, else there 
is danger of developing a banking error. An examination of the 
highest grade watches will reveal the fact that arcs of 450 degrees 
are most favored. 



16 



LESSON 5 



PALLETS— CIRCULAR, EQUIDISTANT AND 
DRAFTING 



110. Form of Pallet Jewel. — The acting faces of a pallet jewel 
are A B and AC (see Fig. 6). The part A B is the jewel's locking 
face. Upon some part of its surface the escape wheel tooth drops 




and locks. Notice the slant of A B away from the point B. 
A B is shown as an inclined plane.. The purpose of this slant is 
to help draw the pallet jewel deeper into the escape wheel and to 
hold the lever against its bank. The force which produces the 
effects just mentioned is termed "draw." That part of the pallet 
from B to C is termed the lifting or impulse face of the pallet 
jewel. The impulse face assists in moving the lever from hank to 
bank. It is directly associated with the lifting face found on a 
tooth of the escape wheel. The combined lifting or impulse faces, 
located on tooth and pallet, are directly responsible for the blow 
given to the roller jewel by the slot in the fork. 

111. Angles Shaping the Pallet Jewel. — The angles which con- 
trol the shape of a pallet jewel are three in number. These three 
angles arise from three different points, namely, the pallet center 
at D, the escape wheel center at E and the pallet corner at B (see 
Fig. 7). 



17 

112. Angle of Impulse. — The angle H D K (Fig, 7) arises at 
the pallet center D. This angle is known as the impulse or lifting 




angle. The impulse angle in conjunction with the angle of width, 
viz., PEG (Fig. 7), defines B C, the pallet's impulse face. 

113. Angle of Width. — The width of a pallet jewel is governed 
by the size of the angle F E G, the point of origin of this angle 
being the escape wheel center E (Fig. 7). 

114. Draft Angle. — The draft angle F B A (Fig. 7) starts 
from the point B. This point is located at the lowest locking 
corner of the pallet jewel. The degrees of slant of the line 
A B are reckoned as away from the line F B. 

115. Angle of Lock. — The angle of lock of tooth on the pallet 
jewel is not represented in the drawing (Fig. 7) for the reason 
that the angle of lock has nothing to do with the shape of the 
pallet stone. 

116. Circular Pallets. — The type of pallet used in American 
watches is known as the "circular pallet." The locking face of 
the entering pallet jewel is further from the pallet center than is 
the locking face of the exit pallet. That part of each pallet stone, 
situated midway betwixt the entering and discharging corners of 
the pallet's impulse plane, is at an equal distance from the pallet 
center. Pallets of the circular type are easily recognized by 
means of a depthing tool. The V-shaped end of the sliding rod 



18 

of the depthing tool is placed over the pivot of the pallet staff and 
the tool adjusted so that the sharp point of the other rod touches 
the locking corner of the receiving pallet. It will then be found, 
on swinging the point of the tool over the opposite pallet, that the 
tool's point just touches the discharging corner of the exit pallet. 
If we adjust the point so it stands centrally over one pallet it 
will be found that the point also stands centrally over the opposite 
pallet. In this manner we can prove if pallets are of the circular 
type. 

117. Equidistant Pallets. — Equidistant pallets are found only 
in the higher grades of foreign-made watches. They are easily 
recognized by using a depthing tool in the manner previously 
described. We will, however, find this difference, that with the 
point adjusted to touch the lov/est locking corner of the entering 
pallet, and then swung over on to the exit pallet, the point of the 
tool will be found to touch the locking corner of the exit pallet. 
This experiment will prove that the locking faces are equidistant 
from the pallet center; therefore the term "Equidistant Pallets" is 
used to describe them. 

118. Drafting Circular Pallets. — We shall now briefly explain 
the drafting of a circular pallet. It is not the purpose of these 
lessons to delve extensively into the subject of drafting. If we 
were to attempt it an entire volume v/ould have to be devoted 
to the subject. Besides, from the writer's experience, personal 
instruction is necessary if the student is to greatly profit from 
the making of complete escapement drawings. Our present pur- 
pose is to supply the student with the simplest theoretical explana- 
tion of the various escapement parts. This will be sufficient to 
insure a foundation for further advancement in this interesting 
and useful branch of educational horology. 

119. Specifications. — Distance of center of receiving pallet to 
center of exit pallet, 60 degrees; width of pallets, 6 degrees; lift 
on pallets, 5i/^degrees; total lock, 2 degrees. Of the total lock 
1% degrees is drop lock, the remaining one-half degree being 
slide. Draft angle on pallet, 12 degrees. Commence by drawing 
the line B H (Fig. 8); the point B represents the escape wheel 
center. Somewhere along the line B H the pallet center will be 
located. Its location will be later determined. With B as center, 
describe the arc C C. On each side of the line H B lay off two 
angles, each containing 30 degrees. The angles D B H and H B E 
each contain the required 30 degrees. Draw the lines F A and 
A G; these lines intercept D B and E B exactly at right angles. 
The lines F A and A G are tangents to the circle C C and meet at 
the point A on the line B H. Their meeting point is at A, the 
pallet center. Our specifications call for a pallet width of 6 
degrees. As we are dealing with circular pallets, we accordingly 
lay off one angle of 3 degrees to the left of the line D B and 



19 




20 

another angle of equal size to the right of D B. The angle 
K B L is therefore one of 6 degrees, as called for by our specifica- 
tions. The angle of lock is to equal 2 degrees, therefore below 
the tangent line P A we lay out the angle F A O, containing 2 
degrees. At the point where the line A intercepts the line K B 
we locate the corner of the pallet jewel (see P in drawing). Prom 
P, and away from the line P K, we lay off an angle of 12 degrees, 
as shown by K P R. This is the draft angle of the pallet, and 
accordingly R P is the pallet jewel's locking face. Below the line 
O A lay off an angle of 5i^ degrees. The angle A S is the 
required angle. This is the angle of lift for the pallet stone. 
Observe where the line S A and B L cut each other; this point 
we have marked T. Connecting the point P with the point T 
gives us the line P T. This line marks out the lifting or impulse 
face of the pallet jewel. The back of the pallet jewel N T is 
simply drawn parallel to the locking face R P, which completes 
the drawing. 



21 



LESSON 6 



THE ESCAPE WHEEL— DRAFTING 



120. Escape Wheel Teeth. — The acting parts of a club tooth 
are two in number, namely, the lifting plane A B (Fig. 9) and 
the incline B C which starts at the locking corner B. Of the whole 
line B C practically the corner B alone comes into action, this 




being the part which rests on the pallet jewel's locking face. The 
line A N takes no part in the escapement action, the undercutting 
from the point A being for clearance between pallet and tooth. 
This statement, like others, should be verified by the student from 
actual observation of an escapement in action. 

121. Tooth's Impulse Face. — The lifting face or impulse plane 
of a tooth is defined by the line A B (Fig. 9). The impulse face 
on the tooth combined with the impulse plane on the pallet jewel 
imparts, through the medium of the fork, the force necessary to 
keep the balance vibrating. 



22 

122. Tooth's Draft Angle.— T^q line B C (Pig. 9) of the tooth 
is given a very decided slant in order that only the corner B will 
rest against the locking face of the pallet jewel. The effect is, 
that friction between tooth and pallet is lessened. This reduction 
of friction greatly improves the "draw." The purpose of draw Is 
to retain the lever against its bank. 

123. Angles Shaping a Tooth. — The angles which give shape 
to a club tooth are three in number. They are the angle of width 
which defines the width of the tooth, the angle of impulse which 
governs the amount of lift and the angle which gives form to the 
slant on the back of the teeth. These angles arise from three 
different points. 

124. Angle of Impulse. — The angle controlling the amount 
of impulse or lift on a club tooth originates at K (Pig. 9), the 
point K being the pallet center. This angle is illustrated as 
enclosed between the lines G K H. 

125. Tooth's Angle of Width. — The width of a tooth of the 
escape wheel is governed by the angle P E D (Pig. 9). The 
starting point of this angle is at E, the escape wheel center. 

126. Tooth's Draft Angle. — The draft angle, or angle which 
defines the slant B C, is shown as enclosed by the lines E B R. 
The starting point of this angle is at B, the degrees of slant 
being reckoned away from B E. Should we desire to make a 
complete drawing of an escape wheel, a number of radial lines 
should be drawn from the locking corner of each tooth to the 
center of the escape wheel. The degrees of slant for B C would 
be counted from each line as illustrated by the angle R B E 
(Pig. 9). 

127. The Angle of Drop. — The angle of drop arises at the 
escape wheel center. The amount of the angle of drop in the 
better grade watches is about 1% degrees. In watches of poorer 
construction it is often greater and frequently irregular. A 
practical method for estimating the angle of drop is given in 
Lesson 13. 

128. Drop. — ^When a tooth of the escape wheel becomes de- 
tached from the releasing corner of either pallet jewel a free flight 
of the escape wheel through space results. This free motion of the 
escape wheel is termed its drop. Drop commences the moment 
a tooth separates itself from a pallet jewel and ceases the instant 
another tooth is caught on the intercepting locking face of the 
opposing pallet. We can define "drop" as the space through 
which an escape wheel moves without doing any work. 

129. Drop and Shake. — The angle or amount of drop visible 
in any escapement does not represent the least freedom between 
the pallet jewels and the teeth of the escape wheel. The position 
wherein the least freedom exists between the teeth and pallets 
is spoken of as their "shake." The student should experimentally 



23 

determine the shake or position of least freedom in the following 
way: Bring a tooth down on to the lowest locking corner of a 
pallet jewel and note the space separating the back of the opposite 
pallet from the heel of the tooth just behind it. A brief examina- 
tion will prove that the space so seen, viz., the shake, is less than 
its corresponding drop. The amount of drop and shake present 
in any escapement can in a practical way be estimated by using 
the pallet's width as a standard, as explained in Lesson 13, para- 
graphs 184 and 184A. 

130. Shake. — The amount of shake present in any escapement 
is always closely related to the angle of drop, because shake 
equals the drop minus the recoil of the escape wheel. Like drop, 
we have two classes of shake, namely, outside and inside shake. 
Whenever in an escapement we find the drops unequal we will 
likewise find that the shakes are unequal. A little experimenting 
will prove that it is quite possible to find drop present and the 
corresponding shake absent. Inequalities in drops or shakes will 
not ordinarily prevent a watch running, but a lack of either will 
cause stoppage. The manner of determining the amount of shake 
is explained in our tests. 

131. The CluT) Tooth Escape Wheel. — ^When discusisng the 
pallets we learned that we had two types to consider, namely, the 
circular pallet, as used in American-made watches, and the equi- 
distant, which is used only in the higher grades of imported 
watches. This distinction does not apply to escape wheels, as we 
have but one type of escape wheel readily adapted to either class 
of pallet. 

132. Escape Wheel Specifications. — Number of teeth, 15; pal- 
lets to span 2% tooth spaces. This from lock to lock equals 60 
degrees; distance from heel of one tooth to heel of following tooth 
to be 24 degrees (360° ^15 = 24°). To obtain the number of 
degrees suitable for combined width of tooth, pallet and angle of 
drop we divide 24 degrees by 2, the result being 12 degrees. Of 
this sum we assign 6 degrees for width of pallet, the remaining 
6 degrees being divided as follows: For the width of tooth, 4l^ 
degrees, and for the angle of drop, ll^ degrees. The draft angle 
or slant of the teeth is to equal 24 degrees, the lift or impulse 
angle to be 3 degrees. 

133. How to Draft an Escape Wheel. — Let the line X B (Fig. 
10) be the line of centers. With B as the center of the escape 
wheel and N as the radius, describe the arc C N C, This is the 
primitive or first circle of the escape wheel. Upon this circle the 
locking corners of all the escape wheel teeth will rest. On each 
side of the line B X lay off two angles each containing 30 degrees. 
The angle D B X and X B E each contain 30 degrees. Where the 
lines B D and E B intersect the arc C C we have marked T and 
U. Through these points draw the lines G A and H A tangent 



24 



^O 




C-^--^ l-^ 



Fig. 10 



25 

to the arc C C . The tangent lines G A and H A meet on the line 
B X, namely, at A, this being the pallet center. Above the tangent 
line G A lay off an angle of 3 degrees as shown enclosed by the 
lines K A G. This is the angle of lift for the teeth of the escape 
wheel. Where K A intersects the line D B we have marked S'. 
With B as center and B S' as radius draw the arc O, This 
is known as the lifting or addenda circle. The space separating 
the arcs O O and C C will, when the teeth are correctly drawn in, 
provide for the lifting or impulse face. According to our specifi- 
cations the lift on the teeth is 3 degrees. The toe of each tooth 
will rest on the arc C C, while the heel of each tooth will touch 
the arc 0. The width of a tooth is next drawn in. The required 
width being 4^^ degrees, we lay out the angle P B D. Where 
P B intersects the arc O is marked S; by drawing a line con- 
necting S with T we define the tooth's lift or impulse plane. To 
mark out the slant of a tooth we place the center of the pro- 
tractor at T, with the 90 degree mark extending along the line 
T B. We then count off 24 degrees as represented by the angle 
M T B. The line T M is the slant of the tooth, or, as previously 
mentioned, it may be called the draft angle of the tooth. The 
undercutting S to P is not obtained in obedience to any angle, 
the only rule which applies being that the undercutting should be 
of such extent that whenever the pallet dips into the wheel no 
contact of the parts is possible. To illustrate how other teeth can 
be drawn in we measure off 24 degrees on the arc C C away from 
the toe of the tooth already formed. From this point, marked Y, 
we draw the radial line Y B. From the point Y, away from the 
line Y B, an angle of 24 degrees is laid off, thereby defining the 
tooth's draft angle, as shown by B Y Z. Next an angle of 4^4 
degrees in width is laid out, its point of origin being the escape 
wheel center. The lines R B Y enclose the required 4% degrees. 
Where the line R B cuts the arc O O we have marked W. Con- 
necting the points W and Y gives us the lifting face of this tooth. 
If a student desires to make a drawing of an escape wheel showing 
the 15 teeth it is advisable first to space off the primitive circle 
into 15 divisions 24 degrees apart. Drawing in each tooth as 
spaced will yield an irregular drawing. Hence the advice: make 
the divisions first, then draw in the outlines of each tooth. 



26 



LESSON 7 



THE LEVER— DRAFTING 



134. The Lever. — The lever is a straight metal bar attached to 
or a part of the pallet arms. The end of the lever, known as the 
fork, is illustrated in Fig. 11. 

135. Form of Fork. — The fork parts are the horns, the corners 
of the slot, or notch, and the slot. The horns (Fig. 11) are shown 




Fig. 11 

from F to A and D to E. The corners of the notch are respectively 
marked A and D. The slot is enclosed by the lines A B, B C, C D. 

136. The Slot Corners. — In a single roller escapement only 
very short horns on Ihe fork are necessary. In fact, the main 
parts of the lever horns are the corners A and D, together with a 
very slight amount of horn to fully insure the soundness of the 
escapement action. The preservation of the safety action, by 
means of the slot corners, is intimately associated with the action 
of the roller jewel. This will be explained when we consider the 
question of the safety action. 

137. The Slot.— The slot or notch is A B C D, illustrated in 
Fig. 11. Its purpose is that of receiving the roller jewel. The 
moment the roller jewel enters the slot it strikes one side of the 
notch a blow. The effect of this blow is, first, to lift the lever 
away from its bank; second, it causes unlocking of tooth and 



27 

pallet; third, just as unlocking takes place the lifting angles of 
tooth and pallet combined cause the opposite side of the slot to 
deliver a return blow to the roller jewel. This sets the balance 
vibrating with renewed energy. It is desirable to remember two 
points related to the above action; first, the speed of the roller 
jewel is checked and decreased by the force consumed in striking 
the unlocking blow; secondly, the speed of the lever through the 
energy developed by the lifts becomes greater than the speed 
of the roller jewel. In the lifts on tooth and pallet we have the 
reason why the opposite side of the slot delivers the return blow 
which keeps the balance vibrating. 

138. Angles of the Fork. — The angles relating to the fork all 
originate from the pallet center. They are four in number, as 
follows: First, the angle governing the width of the slot; second, 
the angle of freedom for roller jewel when within the slot; third, 
the angle of freedom which controls the space separating the slot 
corners from the path of the roller jewel; fourth, we shall include 
with the fork angles that angle which separates the guard pin 
(lever against bank) from the edge of the table roller. 

139. Fork Specifications. — Angular motion of lever, IQi^ 
degrees; width of slot, 5 degrees. Acting length of lever to 
equal the distance between the centers of escape wheel and 
pallets. The angular motion of the lever consists of the following: 
Lift on tooth, 3 degrees; lift on pallet, 5% degrees; total of drop 
lock and slide, 2 degrees. 

140. Drafting a Fork.— luet A B (Pig. 12) be the line of 




28 

centers, A being the pallet center. With A as center, and a 
radius equal to the distance between the escape wheel and pallets, 
draw the arc C C. Upon some part of the arc C C the slot corners 
will be located, consequently this arc defines the acting length of 
the lever. The angular motion of the lever equals IQi/^ degrees; 
therefore on each side of A B lay off two angles of 5^ degrees 
each as shown by D A B and B A E. The width of the lever slot 
is given as 5 degrees. To define this angle lay off on each side of 
the line D A two angles, each possessing 2i/^ degrees. The whole 
angle H A O is therefore one of 5 degrees. H and O represent the 
slot corners, hence we draw in the lever slot as defined by 
H K S 0. The horns are then drawn in to suit the requirements 
explained in the chapter on the safety action. The angle which 
provides freedom between the roller jewel and slot corners and 
the angle allowing freedom between the guard pin and the edge 
of the roller are both closely associated with the maintenance of 
the Safety action. These we shall consider in due course. (See 
Lesson 15.) In order to make certain points more clear and plain 
the drawings are illustrative in character. If drawn to scale 
their diminutive size would rather confuse than otherwise. 



29 



LESSON 8 



THE ROLLER JEWEL 



141. The Roller Jewel. — The roller jewel or impulse pin is a 
cylindrical-shaped jewel inserted into the table roller. About one- 
third of a roller jewel's cylindrical face is flattened off. The old 
style round jewel pin necessitated the opening of the bankings 
to an unnecessary extent. The result obtained by flattening the 
roller jewel is, the angular motion is lessened, or, to express it 
another way, the lever's motion from bank to bank is decreased. 

142. Action of a Roller Jewel. — When a watch is running the 
roller jewel enters the lever-slot and strikes one side of the notch 
a blow. The force of this blow lifts the lever off its bank and 
unlocks the tooth and pallet; the escape-wheel tooth then enters 
on to the pallet jewel's impulse plane. The direct effect derived 
from the contact of the two lifting planes is to cause the opposite 
side of the slot to deliver a return blow to the roller jewel. It is 
this blow which causes the vibration of the balance. This action 
of giving and receiving a blow is kept up until the watch runs 

143. Angles Relating to the Roller Jewel. — The width of the 
roller jewel is obtained by an angle whose starting point is the 
pallet center. The width of the roller jewel is naturally related 
to the width of the fork slot. The slot's width must always 
exceed that of the roller jewel, the difference between the widths 
being known as "the freedom of the roller jewel within the slot." 
The angle providing freedom between face of roller jewel and 
slot corners arises at the pallet center and is illustrated in Fig. 
13 (ABC). This angle is of great importance in relation to the 
safety action, as we shall later explain. The roller jewel's angle 
of contact or arc of contact with the fork is technically spoken 
of as the impulse angle of the roller jewel. The distance from 
the balance center to the face of the roller jewel is termed the 
impulse radius or the roller-jewel radius. The distance between 
the balance and pallet centers is controlled combinedly by the 
angle relating to the lever's angular motion and the angle of 
impulse. Given these angles we can calculate the distance the 
pallet and balance centers should be apart. It has not been 
thought necessary to make a theoretical draft of the roller jewel's 



30 

position as it relates to the slot corners. The graphic drawing 
(Fig. 13) conveys all the practical information that one drawing 
can convey, which is, that a roller jewel requires a certain amount 




Fig. 13 

of freedom when passing the slot corners under normal escape- 
ment conditions — by which we mean that slide is present. Our 
lessons, practical and theoretical, on banked to drop positions 
and on the safety actions will be found much more beneficial than 
any extended explanatory instruction on drafting a roller jewel 
in position. The same statement applies to instructions for the 
drafting of a table roller. 

144. Tlie Table Roller. — The table roller in an escapement 
possessing but one roller has two functions — first, to hold the 
roller jewel; second, its edge is an important feature of the safety 
action. In a double-roller escapement we have two rollers. The 
larger roller is termed the impulse roller and carries the roller 
jewel. The smaller table is "known as the safety roller and is 
entirely associated with the safety action. The action of these 
rollers will be found explained in our chapters on the safety 
action. 

145. Roller's Angle of Freedom. — The angle which governs the 
amount of freedom between the edge of the roller and the guard 
point originates at the pallet center. This angle is illustrated in 
Fig. 14 by the lines SAN; the amount or extent of this angle 
varies with the type of escapement. For a thorough understand- 
ing of the variations of this angle, either under normal or banked 
to drop conditions, the reader is referred to that portion of this 
book treating on the safety action and its tests. This also applies 
to the requirements of the various escapement types when banked 



31 

to drop, as hereafter described. The angle of freedom of the 
guard point from the edge of the roller is a matter of vital 
importance to the safe action of an escapement. It is also a 




lengthy and somewhat intricate subject, best mastered from 
practical experience as outlined in our tests. 

146. Crescent or Passing Hollow. — The provision of a crescent 
or passing hollow cut into the edge of the roller enables the 
guard pin to pass from bank to bank without touching any part 
of the circumference of the roller. Its purpose is to insure the 
guard pin a free passage under normal conditions. Width and 
depth are its important features (see 198). 



32 



LESSON 9 



DRAW AND ITS EFFECTS IN SINGLE AND 
DOUBLE ROLLER ESCAPEMENTS 



147. Draw. — Draw is a result obtained from two sources — 
first, from the inclination or slant on the locking face of a pallet 
jewel; secondly, from the inclination of the tooth. Only the 
corner of the tooth should touch the locking face of the pallet. We 
might define draw as the force, or as the mechanical suction 
which under normal escapement conditions holds the lever against 
its bank. The cause of draw is located in the pallet and tooth 
action, aided by the power of the mainspring. The effect of draw 
is shown by the lever and its parts. 

148. Slide Lock, Its Relation to Draw. — If we observe an 
escapement in action we will see the instant a tooth drops and 
locks on a pallet jewel that the pallet immediately starts to dip 
into the wheel, thereby increasing the amount of lock. This 
increase of the lock is spoken of as the slide or as the slide lock. 
This sliding lock of the pallet with the tooth is a product of the 
force termed draw. If the draw is imperfect — that is, weak and 
unable to satisfactorily retain the lever against its bank — the 
associated slide lock will be correspondingly ineffectual. The 
extent of slide is entirely controlled by the banking pins. 

149. Draw, Its Effects. — The amount of draw necessary to 
hold a lever against its bank should be just sufficient to offset the 
ordinary body motions which a watch is subjected to in daily 
use. Should a watch receive an extra hard jolt, and the lever in 
consequence be throv/n away from its bank and the guard pin 
comes in contact with the edge of the roller, the force of draw 
will promptly return the lever to its bank. Unnecessary friction 
between the guard pin and roller is thereby prevented. If the 
draw in an escapement is not strong enough to hold the lever 
against its bank, when subjected to the shocks received in daily 
usage, the lever in such an escapement will frequently be jarred 
away from its bank. Consequently an undersirable amount of 
contact of the guard point with the edge of the roller will result. 
This may cause stoppage, or at least the timekeeping qualities 
of the watch will be seriously impaired. 



33 

150. Draw in Single-Roller Escapement. — In a single-roller 
escapement the effect of draw is important in three positions. 

(1) During such times when the guard pin is outside the 
crescent. 

(2) When the guard finger is within the crescent. 

(3) When the roller jewel is opposite the slot corners. 

Regarding the first, should a watch receive a shock of suf- 
ficient violence to throw the lever away from its bank the guard 
pin will come in contact with the edge of the roller. The action, 
however, of draw immediately returns the lever to its bank, the 
result being that steady contact of the guard pin with the edge of 
the roller is prevented. With reference to our second statement, 
should the lever be thrown off its bank at the moment the guard 
pin enters the crescent a small portion of the curve of the horn 
will come in touch with the roller jewel. If the draw is effective 
the lever promptly returns to its bank. Our third item has 
reference to the possibility of the lever leaving its bank at the 
moment the roller jewel is passing the slot corner, in which event 
the roller jewel and slot corner come in contact. The action of 
draw should then pull the lever back to its bank. In this manner 
draw is a factor in the safety action. 

151. Draw in Double-Boiler Escapement. — In a double-roller 
escapement we have three different phases of escapement action 
wherein draw must be effective. These three positions exactly 
correspond with the requirements as before set forth for a single- 
roller escapement. They are: 

(1) During the time that the guard finger remains outside 
the crescent. 

(2) When the guard finger is within the crescent. 

(3) When the roller jewel is opposite the slot corners. 

As the above items are practically the same as already set 
forth in our foregoing statement on draw in a single-roller es- 
capement, students will find no difficulty in understanding them, 
especially if they follow out in a watch the following experi- 
ments : 

152. Draw. Experiment No. 1. — When the roller jewel is well 
past the end of the horn stop the watch by placing a finger on the 
balance; then with a fine tool, such as a watch oiler, lift the lever 
off its bank, thereby causing the guard pin to come in contact 
with edge of the roller. When the tool is removed, the draw, if 
sufficient, will pull the lever toward its bank. 

153. Draw. Experiment No. 2. — At the moment the guard 
pin or finger arrives just within the crescent stop the watch and 
hold the parts in position. Next, lift the lever off its bank so as 
to produce contact of the lever horn with the roller jewel; this 
done, remove the tool. The action of draw should then be 
sufficient to pull the lever toward its bank. 



34 

154. Draw. Experiment No. 3. — Guide the roller jewel op- 
osite the corners of the lever slot, then hold it there. Next, lift 
the lever off its bank, causing contact of the slot corners with the 
face of the roller jewel. Remove the tool from the side of the 
lever, and the draw, if good, will return the lever to its bank. 
If any defect in the draw is detected by the above experiments it 
should be further confirmed. 

T55. Testing the Draw. — To thoroughly examine the draw 
remove the balance. We should then expect to find, power being 
present, that the lever is at rest against its bank. To apply the 
test lift the lever slightly off its bank, then let it go. If the 
draw is right the lever promptly returns to its bank. Again lift 
the lever off its bank, but this time a little further than before. 
If the draw is sound the lever will again return to its bank. A 
third time lift the lever off its bank nearly to the point of un- 
locking, and, as before, when the lever is released it should return 
to its banking. Should the lever hesitate about returning to its 
bank, assuming that the watch is clean and freshly oiled and that 
the pivots of pallet staff and escape-wheel pinion correctly fit 
their respectice holes, then to overcome the want of draw the 
slant of the pallet jewel's locking face will have to be altered. 

156, Altering Draw. — As a rule, want of draw is generally 
due to a pallet jewel being too straight. To overcome this want 
of slant the stone should be tilted in its setting; experiments are 
advisable. For instance, students should determine for themselves 
the effect of tilting a pallet jewel. If the pallet jewel experi- 
mented upon fits tightly in its seat substitute a thinner stone, or 
else cut out the walls of the seat; the original pallet jewel can 
then be tilted as desired. Changing the slant of a pallet stone 
necessitates investigating the drops, the shakes and the locks as 
directed in the following chapters. A great deal more could be 
written on the subject of draw, but given the hint that draw can 
be altered by changing the slant of the pallet jewel, students can 
by experimenting on old watches quickly master the correction of 
this defect. 

Also remember when changing the slant of a pallet stone that 
the action of the "lifts" always demand attention. (See Lesson 11.) 



35 



LESSON 10 



DROPS AND SHAKES 



157. Drop. — Drop is the freedom allowed for the action of the 
pallet stones with the teeth of the escape wheel. When a tooth of 
the escape wheel is released from a pallet jewel there occurs a 
free motion of the wheel. This freedom of motion is termed "the 
drop." The drop or free flight of the wheel ceases the instant 
another tooth comes into contact with the locking face of the 
opposite pallet. In all lever escapements two kinds of drop are 
present, namely, outside and inside. These should be equal. 
As drop is a waste of energy and when excessive is injurious to 
close timing, it follows that a large amount of drop is not 
desirable. Theoretically 1% degrees of drop is the standard, but 
In the majority of watches it exceeds the amount stated. In 
Lesson 13 students will find a table by means of which the amount 
of drop can be approximated. 

158. Shake. — Shake, like drop, is divisible into two parts, viz., 
outside and inside shake. The "outside shake" should equal in 
amount the "inside shake." Any given shake, however, is always 
less than its related drop; for instance, the amount of inside 
shake is less than the amount of inside drop. Shake is less than 
drop because of the draft angle of the pallet. If a student will 
observe a tooth in the act of unlocking from a pallet jewel's 
locking face, a pushing back or recoil of the escape wheel will be 
seen, caused as just mentioned by the draft angle on the pallet 
stone. This recoil of the wheel lessens the freedom between the 
teeth and pallet jewels. Hence our statement ''shake is always 
less than drop." Therefore when alterations affecting the drops 
are made, the shakes must be given the consideration they require. 
It is quite possible for an escapement to possess drop, and shake 
be lacking or nearly so. It is also quite certain that a shortage 
of shake in an escapement will cause stoppage. 

159. Drop and Shake — Escape Wheel Defects. — In high-grade 
watches possessing steel escape wheels we generally find the drops 
and shakes approaching perfection. It is mostly among the cheaper 
grades of watches, especially such as have brass escape wheels, 
that we find defects in either drop or shake, or both. As brass is 



36 

not rigid like steel, this is one cause of the trouble. The teeth 
in brass escape wheels will get out of shape; some are longer 
than others. The teeth also may not be at an equal distance 
apart, all of which complicates the watchmaker's problem of 
securing safe drop and shake. 

160. Drop and Shake — Drop Lock Defective. — The first thing 
that demands attention when irregularities in the drops or shakes 
are discovered is to examine the locks. By lock we mean drop 
lock exclusively. If the locks are unequal they should be equal- 
ized. Whenever the drops and shakes are found unequal usually 
the locks are unequal. It therefore follows that the correction 
of irregular lock overcomes to some extent irregularities of both 
the drops and the shakes. 

161. Testing Outside Drop. — To test the outside drop allow 
a tooth to be discharged from the exit pallet. The escape wheel 
then moves free. This free motion of the wheel is its outside 
drop. Outside drop ceases the moment another tooth is caught 
on the opposing locking face of the opposite pallet. (See para- 
graph No. 19.) 

162. Testing Outside Shake. — The outside shake is always less 
than its corresponding outside drop, as explained elsewhere. To 
test the outside shake bring the tooth found at rest on the locking 
face of the receiving pallet down to that pallet's lowest locking 
corner, as represented by Fig. 19. Hold the parts in this position 
while you note the amount of space which separates the 'back of 
the exit pallet from the point of the tooth just behind it. The 
space seen represents the least freedom of the escape-wheel teeth 
outside the pallet jewels. (See paragraph No. 22.) 

163. Testing Inside Drop. — To test the inside drop allow a 
tooth to become discharged from the receiving pallet. When this 
happens the escape wheel moves free of all contact. The free 
flight of the escape wheel is known as its inside drop. Inside drop 
ceases the instant a tooth comes in contact with the opposing 
face of the exit pallet. (See paragraph No. 18.) 

164. Testing Inside Shake. — To learn the extent of inside 
shake bring the tooth found at rest on the exit pallet jewel's 
locking face down to the lowest locking corner of the pallet, after 
the manner shown in Fig. 20. Retain the parts in this position 
and observe the space separating the back of the receiving pallet 
from the point of the tooth just behind it. The space so seen 
represents the inside shake. The inside shake is always less than 
its corresponding inside drop. (See paragraph No. 21.) 

165. Correcting Drop and Shake When Tight Inside. — To 
correct drop and shake when deficient inside we should try 
spreading the end of the pallet stones apart. At times it is best 
to spread or tilt both pallet jewels apart. More commonly the 
defective inside shake is cured by the tilting of one stone only. 



37 

When this is the case the question which pallet stone we shall 
tilt comes before us. The answer in a practical way is decided 
by examining the draw. A test of the draw on each pallet usually 
shows draw as less effective on one stone than on the other. 
Therefore the stone to be altered, when possible, is the stone 
showing the poorest draw. If the draw is sound on the exit pallet 
and deficient on the receiving, then in most instances by tilting 
the end of the receiving stone away from the opposite pallet the 
draw can be increased. We must also remember that titling the 
pallet jewel affects the lock, the drop, the shake and the lifts. A 
little experimenting will prove these statements. (Consult para- 
graphs Nos. 487 and 438.) 

166. Correcting Drop and Shake When Tight Outside. — If 
the drop and shake are tight or deficient outside we, as before, 
first see to the drop locks. Should it be desirable to use other 
means than attempting to make a correction by directly altering 
the locks we can do so by bringing the pallet jewels closer to- 
gether, after the manner already described for correcting shake 
and drop when too tight inside. (See paragraphs Nos. 165-167.) 

167. Providing a Safe Amount of Shake hy Altering a Pallet 
Jewel. — To provide a safe amount of shake it becomes necessary 
at times to replace a thick pallet jewel with a thin one. When 
the watch is of a poor type the same effect, namely, substituting 
a thin for a thick stone, can be obtained by means of a diamond 
lap. By using such a tool a part of the back portion of a pallet 
jewel can successfully be ground away. This thins the stone at 
the required place and provides the requisite shake. The fore- 
going in a general way outlines the procedure to be followed. The 
points to be aimed for when tilting, shifting or changing the 
thickness of a pallet stone are to equalize the drops, the shakes, 
the locks and the draw. (Also, consult paragraph No. 171.) 



38 



LESSON 11 



LIFT ON TOOTH AND PALLET, CORRECT AND 
INCORRECT 



168. The Lifts. — The question of lift on tooth and pallet 13 an 
entirely practical one. An irregular action of the lifts prevents 
timing and causes stoppage. The student is therefore advised to 
make a study of the lifts at different phases of the escapement 
action. The manner in which a tooth first enters on to a pallet's 
lifting plane, their central relationship and their relative posi- 
tions when disengaging should be closely studied and understood. 






Fig. 



169. Cerrect Lift.— The drawings (Fig. 15) A, B and C in- 
dicate the average relative positions of a tooth as it passes over 
the impulse face of the receiving pallet. The drawings (Fig. 16) 




D, E and F show the average relative positions of a tooth as it 
travels over the discharging pallet's impulse face. 



39 

170. Incorrect Lift. — Not infrequently we encounter lifting 
actions of an irregular nature, such, for instance, as illustrated 
in Fig. 17. This drawing shows that the pallet acts on the tooth 




Fig. 17 

in -place of the tooth acting on the pallet. In Fig. 18 we have 
represented a disengaging action wherein we again find that the 
pallet corner is scraping the tooth's lifting plane. Errors such as 




Fig. 18 

shown in Figs. 17 and 18 must never be allowed to go uncorrected. 
Watches possessing this fault are a source of worry to untrained 
watchmakers and are entirely unsatisfactory to their owners. 
171. Correcting Lifting Errors. — Errors in lift are generally 
attributable in old watches to mismatched parts. When the 
trouble is due to an unsuitable pallet jewel it should be replaced 
by one of correct form and make. Irregularities of the lifts are 
sometimes discovered in new watches. When such is the case 
the watch should be returned to the factory for correction. Our 
own experience is that the factory simply cuts the sides of the 
container holding the pallet jewel; this allows the stone to be so 
tilted that the error in lift is overcome. As watchmakers are not 
lapidaries, cutting the seat is their only solution of the problem. 
Changing the slant of a pallet jewel always brings with it ques- 
tions of draw, drop, shake and lock. With these subjects we must 
be thoroughly familiar, including the topic of "Lift." 



40 



LESSON 12 



TOTAL LOCK— DROP LOCK— SLIDE LOCK- 
BANKED TO DROP— BANKING PINS 



172. The Locks. — It is very important that students verify 
in an escapement the statements in this and other paragraphs 
presented in Lesson 12. They contain practical essentials that 




Fig. 19 

students must be familiar with. The total loch of a tooth of the 
escape wheel on a pallet jewel is composed of two items, viz., drop 
lock and slide lock. 

173. The Drop Lock. — Drop lock takes effect the instant a 
tooth drops on to the locking face of the pallet jeweL The extent 
or amount of drop lock is estimated from the lowest locking 




Fig. 20 

corner of the pallet up to that point on the pallet's locking face 
where the tooth dropped. Let B (Fig. 21) represent the point 
upon which the tooth dropped, then the distance from B to A 
shows the extent of drop lock. Drop lock is not a product of the 
banking pins. The banking pins simply mark out, when so 
adjusted, the position where drop lock takes place. The extent 



41 

of drop lock is entirely due to the position in which we place the 
pallet jewels — that is, in or out, as the condition of the escape- 
ment may require. Book knowledge of drop lock, especially of the 
theoretical variety, is of little benefit to the student, because drop 




Fig. 21 

lock is not a separate entity. It is one part of a whole, one link 
in the escapement. It is a varying quantity in nearly every 
watch, as every experienced watchmaker realizes. Drop lock, light 
or deep, is a question reaching further than the mere fact of 
lock itself. The tests and lessons to follow will bring this out 
clearly. For practical reasons we shall ask students to work out 
drop lock problems in connection with our tests. Thereby they 
can gain a practical knowledge of "correct lock." 

174. Slide Lock. — Slide lock is the after or secondary lock 
which, when the bankings are opened out, follows drop lock. In 
Fig. 21 B to C represents the slide lock. Slide lock is therefore 
an after effect following drop. Slide lock and draw combinedly 
cause the pallet to dip deeper into the wheel. The extent of 
slide is entirely controlled by the banking pins. Every escape- 
ment in normal running condition must show slide. Therefore 
after making an escapement test under banked-to-drop rules it is 
necessary to restore the slide. This is done by spreading the 
bankings. Why slide is necessary will be better understood when 
the tests and safety actions are studied. We shall make this 
brief statement regarding it: By providing an escapement with 
slide it insures greater separation of the guard point from the 
edge of the roller when the lever rests against its bank. 

175. Total Lock. — The total lock of a tooth on a pallet jewel 
is the sum of the drop lock plus the slide lock. In Fig. 21 A to B 
is the drop lock and B to C the slide; therefore A to C represents 
the total lock. 

176. Remaining or Safety Lock. — This is best learned by 
making the following experiment: Bring the guard point of a 
sound escapement into contact with the edge of the roller, then 
observe the tooth and pallet. Whatever amount the tooth remains 
locked on the pallet jewel's locking face represents the remaining 



42 

or safety lock (Fig. 22). If the safety lock is wanting, that is, if 
the tooth enters on to the pallet jewel's impulse face (Fig. 23) 
while the guard point is held in contact with the edge of the 




Fig. 22 

table roller, then the error known as tripping is present. This 
defect we shall treat on in due course. 

177. The Three Safety Locks. — In every escapement a safety 
lock is required as follows: (1) When the guard point touches 




Fig. 23 

the roller. (2) When the roller jewel touches the curve of the 
lever horn. (3) When the slot corners of the lever and roller 
jewel are brought into contact. For further particulars see guard, 
corner and curve safety tests. 

178. The Banking Pins. — The banking pins are the two 
eccentric pins placed on each side of the lever. By means of the 
banking pins we can increase or decrease the slide lock. To a 
certain extent we can adjust them to control the distance between 
the guard point and the edge of the roller. With them we can 
also, within certain limits, control the extent of the roller jewel's 
contact with the walls of the lever slot. We can also adjust them 
to mark out that important position termed "banked to drop." 

179. Banked to Drop. — The expression "banked to drop" 
conveys the fact that both banking pins are so adjusted that im- 
mediately a tooth drops and locks on a pallet jewel the lever that 
instant meets its bank. In an escapement of the Elgin type, when 
banked to drop, a slight space or freedom will be found separating 
the guard point from the roller. In escapements of the South 
Bend type, when banked to drop, the guard point will be found 



43 

in contact with the edge of the roller. All escapements perfectly 
banked to drop show no slide and, consequently, no run of the 
lever. This condition, especially in cheaply made watches, is 
unattainable because of the varying lengths of the teeth of the 
escape wheel. Draw, however, is and should be present. When 
we find an escape wheel with teeth of irregular length perfect 
banked-to-drop conditions are impossible to obtain. Some of 
the teeth will be exactly banked to drop; others will show slide. 
The defect cannot be overcome without a change of escape wheels. 
This rarely pays where cheap watches are concerned. 

Banked to drop is the key which unlocks escapement diffi- 
culties. It will be found a splendid help in unraveling escape- 
ment errors. 



44 



LESSON 13 



MEASUREMENT OF LOCK—APPROXIMATING— 
DEGREES OF LOCK AND DROP 



180. Measurement of Lock. — The measure of one degree of 
of lock depends entirely on the size of the circle of which the 
degree is the l-360th part. To learn how much one degree 
measures we must be acquainted with the length of the radius. 
In other words, we must know the measure of the distance 
separating the lowest locking corner of the pallet jewel from the 
center of the pallet staff. Given the measure of this distance we 
can, by means of the following rule, calculate the size of one 
degree of lock: 

Example — The distance from the lowest locking corner of 
the pallet jewel to the pallet staff center measures 2.5 millimeters. 
Find the measure of one degree of lock. 

Rule — Radius X 2 X 3.1416 ^ 360 = measure of 1° of lock. 

2.5 X 2. = 5. 
5 X 3.1416. = 15.7080. 
15.7080 -- 360. = .044. 

The answer — .044 millimeters is the measure of one degree 
of lock in this escapement. 

181. Approximating Degrees of Loch in Any Escapement. — 
The watchmaker should cultivate his eye to estimate the number 
of degrees of lock of a tooth on a pallet. As an aid toward this 
we divide up the width of a pallet jewel. Assuming that the full 
width of a pallet (see Fig. 21, A to K) approximates 10 degrees 
of lock, then if a tooth is locked on a pallet to an extent equalling 
one-half the width of the pallet we are safe in saying that the 
said tooth is locked on the pallet jewel to the extent of five 
degrees. The width of a pallet means the distance across the 
stone's impulse face from its entrance to its exit corner. Students 
must not confuse an estimation of the extent of the drop with an 
estimation of the amount of lock. As regards the lock, one-fifth 
of the pallet's width equals two degrees of lock, but when we 
estimate the drop, then one-fifth of the width of the pallet jewel 
equals one degree of drop. (See paragraphs Nos. 183 and 184.) 



45 

182. Estimating the Angle of Drop. — We can estimate the 
angle of drop in an escapement as before, by considering the width 
of the pallet as our standard of measure. The angle of drop and 
the angle of controlling the width of a pallet jewel are measured 
from the same point, namely, the escape wheel center; this makes 
them closely related. Therefore accepting the width of a pallet as 
five degrees, we can readily realize that if a tooth drops to an 
extent equalling" one-half the width of the pallet the drop will 
equal 21/^ degrees. In this maner it is easy to approximately 
estimate the angle of drop in an escapement as well as the amount 
of shake. 

183. Table for Approximating Degrees of Lock. — 

1/10 width of pallet equals 1° of lock. 

1/5 width of pallet equals 2° of lock. 

iy4 width of pallet equals 2%° of lock. 

% width of pallet equals 5° of lock. 

% width of pallet equals 7%° of lock. 

1 width of pallet equals 10° of lock. 

184. Table for Approximating Degrees of Drop. — 

1/10 width of pallet equals %° of drop. 

1/5 width of pallet equals 1° of drop. 

1/4 width of pallet equals 11/4" of drop. 

% width of pallet equals 2%° of drop. 

% width of pallet equals 3%° of drop. 

1 width of pallet equals 5° of drop. 

The basis of the above figures accepts a pallet width of 5 
degrees as its standard. In an earlier lesson on pallet drafting 
the pallet width was given as 6 degrees. As a matter of fact, 
the width of pallet generally used with escape wheels having club 
teeth varies from 5 to 6 degrees. As an estimate of the lock or 
drop made simply by an observation can only be approximate, the 
figures in the above table are therefore sufficiently close to 
apply to either width of pallet. 

184 A. Approximating Degrees of Shake. — As shake and drop 
are intimately related, we can, when necessary, apply the above 
table of drop to estimate the degrees of shake. 



46 



LESSON 14 



ROUTINE ACTION OF THE SINGLE ROLLER 
ESCAPEMENT— IMPORTANT GUARD 
PIN POSITIONS 



185. Routine of Escapement Action. — If we observe an es- 
capement in action under normal conditions, namely, with slide 
present, and we commence our investigations at the time the 
lever is at rest against its bank, a tooth locked on pallet jewel 
and the roller jewel starting on its return journey toward the 
slot, an analysis of the routine action of the escapement would 
read as follows: 

First Observation — Tooth locked on the pallet. 

Second Observation — The roller jewel is traveling toward the 
lever slot. 

Third Observation — Just before the roller jewel starts to 
enter the slot the guard pin enters the crescent. 

Fourth Observation — The roller jewel enters the slot and 
strikes one side of the slot a blow. 

Fifth Observation — The blow delivered by the roller jewel 
against the side of the lever slot causes unlocking of tooth and 
pallet, thereby allowing the unlocked tooth to slip on to the pallet 
jewel's impulse face. 

Sixth Observation — Through the meeting of the lifting planes, 
of tooth and pallet, aided by the power of the mainspring, the 
opposite side of the lever slot delivers a blow to the roller jewel. 

Seventh Observation — This blow causes the balance to rotate 
with renewed energy. 

Eighth Observation — When the tooth left the discharging 
corner of the pallet it dropped (drop) and another tooth locked 
on the opposing pallet (drop lock). 

Ninth Observation — When drop lock takes effect the guard 
pin theoretically is within the crescent, but practically considered, 
owing to the velocity of the parts, the guard pin is leaving the 
crescent. It is at this phase of the escapement action that the 
guard pin comes closest to the edge of the roller. The position of 
the guard pin just mentioned must always be kept in mind by 
the repairer, especially when circumstances require us to adjust 



47 

the guard pin a trifle closer to the edge of the roller than is 
really desirable. 

Tenth Observation — Immediately drop lock takes place the 
pallet slides deeper into the wheel (slide lock). The deeper the 
pallet slides into the wheel the further the guard pin is carried 
away from edge of the roller. 

Eleventh Observation — Coincident with the increase of the 
slide lock in the lun of the lever toward its bank. When the lever 
arrives at its bank the guard pin is then furthest from the edge 
of the roller. The cause of the effects noted above, viz., slide 
and run, is entirely attributable to draw. 

Twelfth Observation — The amount of slide lock, the amount 
of run and the distance separating the guard pin from the edge 
of the roller are three correlated effects. The amount of each is 
normally controlled by the position of the banking pins. 

186. Important Guard Pin Positions. — We wish to impress on 
students the following three positions of the guard pin. It is 
advisable that actual observation of the described actions be 
followed out in an escapement: 

First Position — When the roller jewel enters the notch, pre- 
paratory to striking the unlocking blow, the guard pin is within 
the crescent. 

Second Position — As a tooth of the escape wheel drops on 
the locking face of the pallet jewel the guard pin, for all practical 
purposes, owing to the velocity of the parts is barely outside the 
crescent. This means that the guard pin is only clear of the 
roller edge and no more. As previously mentioned, this repre- 
sents the closest the guard pin aproaches the roller edge when 
an escapement is in action. 

Third Position — The next position of the guard pin is when 
the lever is at rest against its bank. Slide lock being present, the 
guard pin is then at its greatest distance from the edge of the 
roller. 



48 



LESSON 15 



THE SAFETY ACTIONS OF THE SINGLE- 
ROLLER ESCAPEMENT— GUARD PIN— 
OVERBANKING— TRIPPING 



187. The Safety Action. — The purpose of the safety devices 
is to insure the escapement continuing in action should the watch 
receive a shock of sufficient force to throw the lever off its bank, 
in which event the parts relating to the safety action come in 
contact and thereby assist in returning the lever to its bank. In 
a single-roller escapement the parts composing the safety action 
are the guard pin, coassociated with the edge of the roller; the 
roller jewel, coassociated with a very short part of the lever horn, 
and the roller jewel as associated with the corners of the slot. 
Most intimately related to the above combinations are the lock of 
the escape wheel tooth on the pallet jewel's locking face and the 
draw. 

188. The Guard Pin's Safety Actions. — The office of the guard 
pin as a safety action factor is as follows: 

(a) To prevent overbanking. 

(b) To prevent tripping. 

(c) To prevent contact of the roller jewel with the greater 
part of the lever horn. This it does up to the moment the guard 
pin enters the crescent. 

Once the guard pin enters the crescent the preservation of 
the safety action then depends upon the roller jewel, associated 
with either a small part of the horn or the slot corner, as 
described in the following: 

189. The Roller JeweVs Safety Actions. — The purpose of the 
roller jewel as a factor in the safety action of single-roller 
escapements is confined to its association with the slot corners 
and that part of the horns close to the slot corners. Its function 
as a imrt of the safety action is to prevent tripping. 

190. Over'banMng. — As previously stated, one of the functions 
of the guard pin is to prevent overbanking. The shocks and jolts 
a watch receives in the course of every-day usage will at times, 
when sufficiently violent, jar the lever away from its bank and 
result in contact of the guard pin with the edge of the roller. If 



49 

conditions are correct the lever returns to its bank. This, of 
course, relieves the pressure of the guard pin against the roller. 
If conditions are incorrect the guard pin slips past the unbroken 
edge of the table. In this event the lever passes to its opposite 
bank and the roller jewel on its return excursion, instead of 
being able to enter the fork, strikes on the outside of the horn. 
Tlie escapement is then in the condition usually termed "over- 
banked." In the ordinary course of an escapement's action the 
lever should never move from one bank to another except when 
under the control of the action of the roller jewel in the lever 
slot. Should the lever jump from one bank to another in an 
irregular manner the escapement is put out of action and over- 
bankifig results. Overbanking, therefore, implies an irregular 
motion of the lever from bank to bank without the aid of the 
roller jewel. It also implies that the safety action failed in its 
function. Failure of the safety action sufficient to allow over- 
banking to take place is attributable to one or more causes. 

191. Causes of Overhanking. — Overbanking is due to some of 
the following defects: A guard pin too far away from the edge 
of the table. A loose guard pin. The edge of the roller running 
out of truth; sometimes this is the result of an attempt to close 
the hole in the roller in an effort to securely fasten it on the 
balance staff. Bent pivots of the balance staff also produce an 
eccentric motion of the roller. A frequent cause of overbanking 
is that of holes too large for the pivots of the pallet or balance 
staff. Jewels loose in their settings, or settings loose in their 
seats. Defective draw, with uncertain adjustment of some parts 
of the safety action, will at times be responsible for an over- 
banking error. 

192. Tripping. — Tripping is the act of a tooth of the escape 
wheel leaving the locking face of the pallet jewel in an irregular 
manner. Any unlocking of tooth and pallet not caused by the 
action of the roler jewel with the slot is an irregular unlocking. 
All watches should be subjected to tests for tripping errors and 
corrections made if an error is found. We have three positions 
in a single-roller escapement wherein tripping errors may develop, 
as follows: 

(a) While the guard pin is outside the crescent. 

(b) When the guard pin just enters the crescent. 

(c) When the roller jewel is opposite the slot corners. 

TRIPPING TESTS (Single Roller) 

193. Guard Safety Test. — First — Place a finger on the balance 
rim and rotate the balance so as to bring the roller jewel beyond 
the end of the horn. 

Second — Hold the balance steady, then with a fine broach 
lift the lever off its bank, thereby bringing the guard pin and 
roller in contact. 



50 

Third — Retain the parts in position and with an eye glass 
note the amount of the remaining or safety lock of the tooth on 
the pallet. 

Fourth — If the tooth remains on the locking face of the 
pallet jewel (Fig. 22) the safety action, so far as tested, is sound. 
If a tooth enters on to the pallet jewel's impulse face (Fig. 23, 
irregular unlocking) the error known as tripping is present and 
calls for correction. The cause of the error might be attributable 
to the drop locks being too light or the guard pin not being 
correctly adjusted to the roller. With the assistance of the tests 
to follow students will be able to locate the cause of error. Should 
we discover at any time a very light safety lock, make a test of 
all the teeth, for the reason that some of the escape wheel teeth 
may be shorter than others. If so, look out for tripping errors. 
Slight trips cause irregular stoppage of the escapement, hence we 
repeat our advice, when the safety lock is extremely light test 
all teeth of the escape wheel. 

194. Corner Safety Test. — First — Rotate the balance so as to 
bring the roller jewel opposite one of the slot corners. 

Second — With a fine tool lift the lever away from its bank 
sufficiently to cause contact of the slot corner with the roller 
jewel. 

Third — We note the condition of the remaining or safety lock. 
The tooth must be found on the locking face of the pallet jewel. 
If a trip is discovered, it must be corrected. The cause might be 
due to the lock, the position of the roller jewel, or to the acting 
length of the lever. The nature of the error should be uncovered 
by means of the angular and corner tests, as explained elsewhere 
in the lessons. 

195. Curve Safety Test. — First — Place a finger on the balance 
and guide it so the guard pin just enters the crescent. 

Second — Hold the parts in this position and with a broach 
or watch oiler lift the lever off its bank, thus causing contact of 
the roller jewel with a small part of the horn near the slot 
corners. How much of the horn can thus be found in contact 
with the roller jewel depends on the size of the crescent. 

Third — Still hold the parts in contact while with an eye glass 
the remaining or safety lock of tooth on pallet is inspected. 

If the relationship of the parts is correct a tripping error will 
not be discovered. As a matter of fact, in single-roller escape- 
ments this part of the test can be omitted, because tripping 
errors rarely develop here. The positions we must test are the 
guard pin against the roller and the roller jewel with the slot 
corner, as stated below. 

LEVER HORNS AND CURVE TEST (Single Roller) 

196. Relation of Horns to Roller Jewel. — In connection with 
our subject a brief repetition of the relation of the lever horns to 



51 

the roller jewel is desirable. The most perfect relationship when 
subjected to test conditions is that of the non-contact of the roller 
jewel with the lever horns while the guard pin remains outside 
the crescent. Once the guard pin enters within the crescent and 
we apply tests, contact of the roller jewel with a very short 
portion of the horn is to be expected. This is one of the features 
of the safety action. Again, when the roller jewel under test 
conditions is brought in contact with the slot corners no decided 
catch of the parts should be found. The roller jewel under test 
cenditions should rub evenly along the short part of the horn 
and past the slot corner without showing any inclination to stick. 
Undue friction developing into a catch of the parts must be over- 
come. The following tests show the relationship of the curve of 
the horn to the roller jewel. 

197. Curve Tests. — First — Place a finger on the balance and 
guide the roller jewel into a position beyond the tip of the lever 
horn. 

Second — With a tool lift the lever away from its bank and 
maintain contact of the guard pin with the edge ®f the roller. 

Third — With all parts held as directed, slowly commence 
rotating the balance, thereby bringing the roller jewel past the 
horn. No contact should be felt. If contact is detected it should 
be only of the slightest character while the guard pin is outside 
the crescent. 

Fourth — Once the guard pin enters the crescent a slight rub 
will be felt of the roller jewel on the horn and on the slot comer 
as it passes. No catching of the parts is permissible, for such a 
defect could produce stoppage of the watch. 

These tests will be found in more concise form in Lesson 31. 



52 



LESSON 16 



ROUTINE ACTION OF THE DOUBLE-ROLLER 

ESCAPEMENT 



198. Routine Action of the Doutle-Roller Escapement. — If we 
observe the routine action of a double-roller escapement when 
running under normal conditions, namely, with slide present, 
the following would be a statement of the actions. Assuming 
that the roller jewel is beyond the horn and the lever at rest 
■against its bank: 

First Observation — Tooth locked on pallet. 

Second Observation — When the guard finger enters the 
crescent the roller jewel is opposite the tip of the horn. 

Third Observation — The guard finger is well within the 
crescent when the roller jewel enters the slot and strikes the 
unlocking blow. 

Fourth Observation — The blow delivered by the roller jewel 
to the lever slot caused unlocking of tooth and pallet. In conse- 
quence the tooth entered on to the pallet jewel's impulse face. 

Fifth Observation — The effect of unlocking resulted as fol- 
lows: The lifting plane of the unlocked tooth, through power 
derived from the mainspring, pushed its way over the impulse 
face of the pallet jewel. The contact of the lifting planes caused 
the opposite side of the slot to deliver a return blow to the roller 
jewel. 

Sixth Observation — The effect of the return blow causes the 
balance to vibrate with renewed energy. 

Seventh Observation — The moment a tooth left the discharging 
corner of the pallet it dropped (drop) and another locked on the 
opposite pallet (drop lock). 

Eighth Observation — When drop lock took effect the guard 
finger was deep within the crescent. 

Ninth Observation — Immediately on completion of the drop 
lock the pallet commenced to dip into the wheel (slide lock). 
As a result the lever runs toward its bank. 

Tenth Observation — The guard finger is far within the 
crescent when the lever starts to run toward its bank. 

Eleventh Observation — When the guard finger emerges from 



53 

the crescent the distance separating the guard finger from the 
edge of the safety roller has been increased by the amount of 
slide lock. To state the foregoing another way, when the guard 
finger emerges from the crescent the lever is at rest against its 
bank and the roller jewel will be traveling toward the extremity 
of the horn. 

Note. — The width of crescent and length of horn are closely 
related. For instance, when the guard finger just emerges from 
the crescent, the length of horn must be such, that its tip is 
opposite the center of the roller jewel. A horn of shorter length 
will cause trouble. 



54 



LESSON 17 



THE SAFETY ACTION OF THE DOUBLE- 
ROLLER ESCAPEMENT— GUARD FINGER- 
ROLLER JEWEL— OVERBANKING— 
TRIPPING 



199. Safety Action — Parts of the Double-Roller Escapement. — 
In a double-roller escapement the parts comprising the safety 
action are: 

(a) The lever horn coassociated with the roller jewel. 

(b) The slot corners coassociated with the roller jewel. 

(c) The guard finger coassociated with the edge of the safety 
roller. 

Closely allied to the above is the lock of the tooth on the 
pallet jewel and the draw. 

200. The Guard Finger's Safety Actions. — The function of 
the guard finger in a double-roller escapement is a preventive 
one, as follows: 

(d) To prevent overbanking. 

(e) To prevent tripping. 

(f ) To prevent the roller jewel touching the tips of the horns. 

201. The Roller Jewel's and Guard Points' Safety Actions. — 
The office of the roller jewel as a factor in the escapement action 
of a double-roller escapement is given below: 

(g) When the guard finger just enters the crescent should 
the lever from any cause be thrown off its bank the roller jewel 
will meet the face of the horn and thereby prevent tripping. 

(h) When the roller jewel is opposite the slot corner should 
the lever at that moment be thrown off its bank the slot corner 
will come in contact with the face of the roller jewel. This 
prevents tripping and insures soundness of this part of the safety 
atcion. 

It can be gathered from the above that just as long as the 
guard finger remains outside the crescent the protection of the 
safety action belongs to the guard finger and the edge of the 
safety roller. Once the guard finger enters the crescent it Is of 
no further use as a factor in the safety action. 



55 

(k) When the guard finger of a double-roller escapement 
enters the crescent the preservation of the safety action is due to:* 
First — The curve of the horn meeting the roller jewel. 
Second — The corner of the lever slot meeting the roller jewel. 

202. Overdanking. — As the causes, of overbanking in a 
double-roller escapement are similar to those already described 
in our treatment of this error in a single-roller escapement it 
will be unnecesasry to repeat it here. 

203. Tripping. — In a double-roller escapement we have three 
positions wherein to suspect the existence of a tripping error: 

(a) While the guard finger is opposite any part of the edge 
of the safety roller outside the crescent. 

(b) When the guard finger enters the crescent and the roller 
jewel is opposite any of the central part of the horn. 

(c) When the roller jewel is opposite the slot corners. 
The tests employed for proving or disproving the existence 

of a tripping error and for determining if length of horn is 
correct are stated in the following: 

TRIPPING TESTS (Double Roller) 

204. Guard Safety Test. — To discover if a trip is possible 
while the guard finger remains outside the crescent, commence 
by rotating the balance so as to place the roller jewel at some 
point beyond the end of the horn. This done, lift the lever off its 
bank, thus causing contact of the guard finger with the edge of 
the safety roller. Hold the parts in contact and use an eye- 
glass to observe the lock of the tooth on the pallet jewel. If the 
safety action is sound, the tooth will be found locked on the pallet 
jewel's locking face. If a trip is discovered, that is, if the tooth 
leaves the locking face and enters ever so slightly onto the stone's 
impulse face the cause must be determined and the error cor- 
rected.. If the error is due to a short guard finger, the finger 
may be stretched to correct the error. If the cause is due to 
defective drop lock, it is an easy matter to see if the lock is too 
light and to make the necessary alteration. Consult article on 
"Tripping in a Single Roller Escapement." 

205. Corner Safety Test. — By bringing the slot corner in 
contact with the roller jewel and then examining the condition 
of the safety lock, it can be learned if the remaining lock is sound. 
If the escapement trips corrections are of course necessary. 

206. Curve Safety Test. — ^When the guard finger is brought 
in contact with the edge of the safety roller and we rotate the 
balance, so as to cause the roller jewel to stand opposite the tip 
of the horn, no contact of the roller jewel with the end of the 
horn is permissible. The parts mentioned should be free from 
each other. If we continue rotating the balance, still maintaining 
the guard finger pressed against the side of the roller, we will 



56 

find that the moment the guard finger enters the crescent that 
the curve of the horn will come in direct contact with the face 
of the roller jewel. Having thus obtained contact of the roller 
jewel with the curve of the horn, take an eyeglass and observe 
the position of the tooth on the pallet jewel. If this part of the 
safety action is sound, the tooth will be found on the locking face 
of the ballet jewel. An incorrect finding would be to discover the 
tooth on the impulse face of the pallet stone. This means the 
escapement trips. Changes are then necessary or the watch will 
stop when in daily usage. 

LEVER HORNS AND CURVE TEST (Double Roller) 

207. Testing the Length of the Horn. — To learn if the horn 
of the lever in a double roller escapement is of correct length, 
lift the lever off its bank, causing the guard finger to come in 
contact with the edge of the safety roller. Keep the parts in 
contact and guide the balance so that the center of the roller 
jewel stands opposite the end of the horn. When the roller jewel 
stands in this position the guard finger will be just outside the 
crescent. Therefore, the length of the horn and the size of the 
crescent are directly related. If the width of the crescent is 
increased, the length of the horns must likewise be increased to 
meet the required conditions, viz., when the roller jewel stands 
centrally opposite the end of the horn, the guard finger must be 
just outside the crescent as before stated. When this specification 
has been met the lever horns are of correct length. 

208. Curve Test. — First — Place a finger on the balance rim 
and guide the roller jewel into position beyond the end of the 
horn. 

Second — With some fine tool lift the lever away from its 
bank, then hold the guard point in contact with the edge of 
table. 

Third — With finger on balance rim, and guard point kept in 
contact with table's edge, slowly turn the balance, thereby 
bringing the roller jewel past the tip of the horn. No contact of 
the roller jewel with this part of the horn is permissible. Should 
any be detected and the parts stick or catch alterations are 
desirable, as instructed in the Test Lessons. 

Fourth — At the moment the guard point enters the crescent 
the horn and roller jewel come into contact and remain so until 
the roller jewel enters the lever slot. Regarding this contact, the 
roller jewel should slide smoothly over the face of the horn and 
past the slot corner without showing any tendency of the parts 
to stick, otherwise stoppage of the watch may result. 



57 



LESSON 18 



SOURCES OF ESCAPEMENT ANGLES 



209. RelationsMp of the Angles. — All angles of freedom are 
measured from the pallet center, the angle of drop excepted. 
Hence with this exception the angles of freedom are correlated. 

The angle of lock is likewise measured from the pallet center. 
This angle is therefore correlated to the angles of freedom which 
originate at the pallet center. Escapement angles having a com- 
mon source are affected by the alteration of one of their number; 
for instance, if we alter the angle of lock, the angles pertaining to 
the safety action reflect the change. For this reason carefulness is 
counseled before vital alterations are made in an escapement. 

210. Source of Escapement Angles. — Judging from the above 
remarks, it is advisable for students to learn the source of the 
various escapement angles, so that previous to an alteration being 
made, a definite opinion can be formed as to the effect of the 
proposed change on some correlated part. 

211. Angles Radiating Toward the Fork — Their Point of 
Origin, the Pallet Center. — A — Angle of freedom of the roller 
jewel from the slot corners. 

B — Angle of freedom of the guard-point from the edge of the 
roller. 

C — In a double-roller escapement the angle of freedom regu- 
lating the distance between the curve of the horn and the path 
of the roller jewel. 

D — The angle of freedom which provides space between the 
end of the horn and the path of the roller jewel. 

E — The freedom angle of the roller jewel when the roller 
jewel is contained within the slot. 

212. Angles Radiating Toward the Tooth and Pallet — Their 
Source of Origin, The Pallet Center. — F — The angle of lock of 
the tooth on pallet. 

G — The angle of lift on the impulse face of the pallet jewel. 
H— The angle of lift on the impulse plane of the tooth. 

213. Angles Arising at Escape-Wheel Center. — K — The angle 
controlling the width of the pallet jewel. 



58 

L — The angle regulating the width of tooth of the escape 
wheel. 

M — The angle controlling the amount of drop. 

214. Source of Other Important Angles. — N — The angle of 
draft which determines the slant of the pallet jewel's locking face. 
It originates at the lowest locking corner of a pallet stone. 

O. The angle which provides the slant found on the locking 
face of a tooth. The angle governing this slant starts from the 
tooth's locking corner. In earlier lessons all of the angles above 
mentioned can be traced in the various drawings and reading 
matter connected with same. 



59 



LESSON 19 



THE SAFETY LOCK IN THEORY AND 
PRACTICE 



215. Remarks Concerning the Safety Actions. — If we are 
given the specifications governing the construction of any escape- 
ment we can therefrom determine the nature of the safety action. 

216. Specifications Relating to the Safety Lock. — Our ex- 
planations apply to the Elgin type of escapement only. Total 
lock, 2 degrees. We assume the total lock to be composed of: 
Drop lock, iy2 degrees; slide lock, Yo degree. Guard-point's free- 
dom from the edge of table roller, with the lever against its 
bank, li>4 degrees. Freedom of roller jewel from the slot corner 
and central part of the horn, 1^/4 degrees, with the lever against 
its bank. Freedom of roller jewel from the end of the horn, with 
the lever against its bank, 1% degrees. 

217. Guard Safety Lock, or Safety Lock Relating to the Guard- 
Point and Roller. — The guard-point's freedom from the edge of 
the roller with the lever against its bank equals 1^ degrees. 
The total lock amounts to 2 degrees. If we bring the guard-pin 
against the edge of the roller we, in consequence, destroy the 
angle of freedom, viz., 1^4 degrees. Subtracting this from the 
total lock, we obtain 2" — 1%°= %°. The answer means that 
when we hold the guard-pin in contact with the edge of the 
roller there still exists a remaining safety lock of % degree. 
This amount is sufficient to insure the escapement action. 

218. Corner Safety Lock or Safety Lock Relating to the Slot 
Corner and Roller Jewel. — The corner of the slot (according to 
specifications) stands, when the lever rests against its bank, 
1% degrees from the path of the roller jewel. The total lock is 
2 degrees, therefore when the corner of the lever slot is brought 
into contact with the roller jewel the angle of freedom (I14 
degrees) is destroyed and the lock of the tooth on the pallet is 
correspondingly lessened, viz., 2° — 1^4° = %°. Our calculation 
shows that when the slot corner and roller jewel touch each 
other the action of the escapement is insured by a safety lock of 
% degree. 

219. Curve Safety Lock or Safety Lock to the Central Part 
of the Horn and Roller Jewel. — In a double-roller escapement the 



60 

instant the guard-flnger enters the crescent the preservation of 
the safety action devolves upon the central part of the lever horn 
and the roller jewel. According to our specifications, when the 
lever is at rest against its bank the roller jewel will be separated 
from this part of the horn by a distance equal to I14 degrees. 
The total lock of the tooth on the pallet with the lever against 
its bank is 2 degrees, therefore when the central part of the 
horn is brought into contact with the roller jewel the safety lock 
will equal 2° — I14, or %°. This safety lock guarantees the 
action of the escapement. 

220. Separation of the Tip of the Horn from the Roller Jewel. 
— The end of the lever horn is, according to specifications, so 
formed that the path of the roller jewel will pass it at a distance 
of 1% degrees when the lever is at rest against its bank. The 
freedom of the guard-point from the edge of the roller when the 
lever rests against its bank equals li^ degrees. If we bring the 
guard-point in contact with the roller and guide the roller jewel 
opposite the tip of the horn, the horn and the roller jewel will be 
separated by a space amounting to % degree, viz., 1%° — li^° 

== 1/2°. 

221. Detrimental Effect of Erroneously Cutting the Lever's 
Acting Length. — ^We made a plain statement in the earlier part 
of the preceding lesson — i. e., when angles arise from a common 
point an alteration of one of the angles is reflected by the 
remaining angles. This statement we shall now prove. As stated 
in our specifications, the angle of freedom of the roller jewel with 
the lever against its bank is li^ degrees. The total lock of the 
tooth on the pallet is 2 degrees. If we cut away the corners of 
the lever slot so as to provide each corner with 2^4 degrees of 
freedom from the path of the roller jewel, when the lever rests 
against its bank, the result would be disastrous to the safety 
action. This is easily proven from our figures. The lock is 2 
degrees, the new freedom of the roller jewel from the slot corner 
is 21/4 degrees. The freedom exceeds the lock. This is an error, 
because if the slot corner is brought into contact with the face 
of the roller jewel the tooth of the escape wheel would, under 
test conditions, leave the locking face of the pallet jewel and 
enter on to the impulse face of the stone, causing a tripping 
error. 

222. Detrimental Effect of Bending the Guard-Pin. — If the 
total lock is 2 degrees and we bend the guard-pin away from the 
roller so that when the lever rests against its bank the guard- 
pin is removed 214 degrees from the edge of the roller, the effect 
on the safety action would be ruinous. Subtracting the lock (2 
degrees) from the freedom (21^4 degrees) shows that the tooth of 
the escape wheel would, under test conditions, enter on the 
impulse face of the pallet jewel; the result would be a tripping 
error. 



61 



LESSON 20 



THEORETICAL AND PRACTICAL ANALYSIS OF 
BANKED TO DROP 



223. Banked to Drop — Its Relation to Drop Lock. — As pre- 
viously defined, banked to drop means that the banking pins are 
turned in to such an extent that slide or second lock is eliminated. 
Therefore when an escapement is truly banked to drop, we find 
present only the drop or first lock. The relation of the drop lock 
to guard and corner freedom we shall now treat on. (Banked 
to Drop.) 

224. Analysis of the Guard Freedom, Banked to Drop — 
Elgin Type. — If we are given the usual figures representing the 
specifications of an escapement, and desire to make an analysis 
of that escapement when same is banked to drop, we must deduct 
the slide from three sources — first, from the total lock; second, 
from the guard freedom ; third, from the corner freedom. 

Specifications not Banked to Drop — Total lock, 2 degrees. 
Of the total lock, ly^ degrees are drop lock and half a degree of 
slide. Freedom of guard point from edge of table, lever against 
bank, I14 degrees. 

To change the foregoing into banked to drop specifications we 
deduct the slide from the total lock and also from the guard 
freedom. 

The banked to drop specifications will therefore read: 

Drop lock, 1% degrees. 
Guard freedom, % degree. 

This means, that when the escapement is banked to drop, and 
the lever at rest against its bank, that the guard point will be 
separated from edge of table % degree. 

It also expresses the fact, that when the guard safety test is 
used a remaining or safety lock of % degree will be found 

(II/2 — 3/^ = 3/J. 

225. Analysis of the Corner Freedom Banked to Drop— 
Elgin Type. — Specifications not banked to drop. Total lock, 2 
degrees, composed as follows: Drop lock, li/^ degrees; slide, i/^ 



62 

degree. Freedom of slot corner from path of roller jewel when 
the lever is at rest against its bank, I14 degrees. 

When we bank this escapement to drop we deduct the 
slide from two sources — first, from the freedom of the slot corner 
with roller jewel (1^ — l^ = %), and also from the total lock 

(2 — 1/2 = iy2). 

The following now show banked to drop specifications: 

Drop lock, iy2 degrees. 
Corner freedom, % degrees. 

This implies that under banked to drop conditions, with the 
lever at rest against its bank the slot corner ana roller jewel 
will be % of a degree apart. 

When the corner safety test is tried we will find a remaining 
or safety lock equal to % degree (1% — % = %)• 
326. Banked to Drop Summary, Elgin Type — 
Guard freedom present. 
Corner freedom present. 
Safety lock always less than the drop lock. 

227. Analysis Banked to Drop — South Bend Type. — Let 2 
degrees represent the total lock in an escapement of the South 
Bend type. Of the total lock 1 degree will represent drop lock 
and 1 degree slide. The amount of slide always equals the corner 
and guard freedoms. The extent of drop lock equals the safety 
lock. When "banked to drop we will find a drop lock of 1 degree 
present. As the corner and guard freedoms equal the slide, these 
freedoms are destroyed by banking to drop. 

228. Banked to Drop Summary — South Bend Type. — 
Guard freedom, none. 

Corner freedom, none. 

Safety lock equals the drop lock. 



63 



LESSON 21 



THE GUARD TEST IN THEORY AND PRACTICE 



229. Theory of Guard Test. — The theory underlying the guard 
test has been partly reviewed in our lesson on the theory of the 
safety actions. To keep the subject distinct we shall again 
briefly discuss same. 

230. Specifications — Elgin Type. — Total lock, 2 degrees. The 
freedom of the guard-point from the roller, 1^4 degrees. 

Note. — Of the total lock 1% degrees is the drop lock, the 
remaining i/^ degree being the slide. 

231. Deductions from the Specifications. — A draft of an es- 
capement made in conformity with the above figures will show a 
tooth locked on the pallet jewel to the extent of 2 degrees, the 
lever being at rest against its bank. The freedom of the guard- 
pin from the edge of the roller will be li/4 degrees. 

232. Guard Test — Deductions Banked to Drop. — If we employ 
the same specifications, but subtract the slide (% degree), our 
new specifications will then read: Drop lock, 1% degrees. The 
freedom of the guard-point from the roller, % degree. 

A drawing made in accordance with these banked-to-drop 
specifications will show the tooth as locked on the pallet jewel 
iy2 degrees. The freedom of the guard-point from the edge of 
the roller will be % degree. The point we desire to impress Is 
that an Elgin type of escapement, when banked to drop, will 
always show freedom between the guard-point and the edge of the 
roller. This is a fact of great practical importance. 

Another fact we wish to be remembered is that an escapement 
of the South Bend type will not show any guard freedom when 
banked to drop; these differences must be kept in mind whenever 
the guard test is used, 

^233. The Guard Test in Practice — Elgin Type. — Beginners 
experimenting with this test are advised to bank every escapement 
to drop; accuracy is thereby attained. Assuming we have an 
escapement before us, the routine of testing the extent of the 
guard freedom is as follows: 

A — The escapement being banked to drop, revolve the balance 
so as to bring the guard-point opposite the edge of the roller as 
shown by Fig. 24. 



64 

B — Hold the parts in the position indicated by Fig. 24. 
C — ^With a watch oiler reach into the movement and lift the 




Fig. 24 

lever away from its bank. This brings the guard-pin in contact 
with the edge of the roller (Fig. 25). 

D — The extent the lever can be lifted off its bank represents 
the freedom of the guard-pin from the edge of the roller. 



CorC^ 




Fig. 25 



E — A similar test should be made on the opposite side of the 
roller. The guard freedoms should be equal. 

234. Some Incorrect Findings Discoverable "by Guard Test— 
Banked to Drop — Elgin Type, — The subject of incorrect findings 
discoverable by the guard test is rather too extensive for con- 
sideration in this part of the lessons. As some aid we briefly 
mention the following: 

235. Example A — Elgin Type. — Should the drop lock In an 
escapement be correct, namely, neither light nor deep, and the 
guard test shows no freedom, banked to drop, between the guard- 
point and the roller, the want of guard freedom will indicate 
that either the guard-point is too far forward or the diameter of 
the roller is too great. 

236. Example B — Elgin Type. — If the drop-locks are deep 
and an excess of freedom is discovered between the guard-point 
and the roller (banked to drop) we can change the error of 
excessive guard freedom into a correct guard freedom by lessen- 
ing the deep lock. 



65 



LESSON 22 



THE CORNER TEST IN THEORY AND PRACTICE 



237. Theory of the Corner Test. — Specifications, Elgin type, 
total lock, 2 degrees. Freedom of the roller jewel from the slot 
corner, ly^ degrees. 

Note. — Of the total lock, % degree belongs to the slide; the 
remainder, viz., l^^ degrees, represents the drop-lock. 

238. Deductions in Accordance with Specifications. — If we 
make a drawing of an escapement, following the figures in the 
specifications, the drawing will show the tooth locked on the 




Corner 

Lcve,r A^^,fnsT 

Fig. 26 

pallet jewel to the extent of 2 degrees. The lever will be at rest 
against its bank and the corner of the lever slot will be separated 
from the path of the roller jewel to the extent of l^, degrees. 
239. Banked-to-Drop Specifications — Elgin Type. — Drop-lock, 
1^/^ degrees. Freedom of the slot corner from the path of the 
roller jewel, % degree. 



66 

Note. — The corner freedom under Mnlced-to-drop conditions 
is obtained by subtracting the slide, % degree from our first 
specifications, 1% — i/^ = s^. 

240. Corner Test — Deductions When Escapement is Banked 
to Drop.— It we follow the specifications, making a drawing 
therefrom, the lever will be shown as at rest against one banking 
pin. If the roller jewel is figured in the drawing as opposite the 
slot corner in the manner shown in Fig. 26 the space separating 
the slot corner from the roller jewel will equal % degree. The 
point we wish to emphasize is that an Elgin type of escapement 
when banked to drop will show, as illustrated in Fig. 26, a little 
freedom between the slot corner and the roller jewel. If a South 
Bend type of escapement is banked to drop no freedom will be 
discovered between the slot corner and the roller jewel. The 
difference between the escapement types with regard to their 
corner and guard freedoms must be remembered and carried into 
actual practice. 

241. The Corner Test in Practice — Elgin Type. — To obtain 
accurate information by the corner test requires that the escape- 
ment be banked to drop. The routine of testing the corner free- 
dom is as follows: 

A — Bank the escapement to drop and revolve the balance so 
as to bring the roller jewel opposite the slot corner, as illustrated 
by Fig. 26. 

B — Retain the parts in position as shown in Fig. 26. 

C — ^With a watch oiler or other fine tool lift the lever away 




Fig. 27 

from its bank. This causes the slot corner to come into contact 
with the roller jewel, as shown in Fig. 27. 

D — The extent we are able to lift the lever away from its 
bank shows the extent of the corner freedom. 

E — Make a test on the opposite slot corner. If conditions are 
correct the corner freedoms will be equal. 



67 

242. Example A — Elgin Type. — ^When the drop-locks are 
correct and the corner test shows no freedom between the slot 
corners and roller jewel, as shown in Fig. 28, we realize that 



Co^^ 




Fig. 28 

either the lever's acting length is long or the roller jewel's position 
is too far advanced. 

243. Example B — Elgin Type. — Should the drop-locks be deep 
and the corner test show an excess of corner freedom the error 
of excessive corner freedom can be overcome and corrected by 
simply decreasing the drop-locks. 



68 



LESSON 23 



SLIDE— ITS RELATION TO CORNER AND 

GUARD FREEDOM— ELGIN AND 

SOUTH BEND TYPES 



Remarks. — Although "slide" and "freedom" have been dis- 
cussed in Lesson 20 and elsewhere, we have, because of their 
importance, given them further and separate consideration. 

244. Slide, and the Provision for Corner Freedom — Elgin Type. 
— If we accept 2 degrees as the total lock belonging to an Elgin 
type of escapement, and of this total allow l^^ degrees for the 
drop-lock, the remaining % degree will be slide. In paragraph 
No. 207 the freedom of the roller jewel from the slot corner, with 
the lever against its bank, escapement not banked to drop, is 
given as 1^ degrees. These figures therefore represent the 
amount of corner freedom when slide is present. 

To estimate the corner freedom when this type of escapement 
is hanked to drop we deduct the slide i/^ degree from the above 
corner freedom of l^^ degrees. Therefore when banked to drop 
the corner freedom equals % degree (1^° — %** = %")• 

245. Slide, and the Provision for Guard Freedom — Elgin 
Type. — Specifications — Total lock, 2 degrees, composed as follows: 
Drop lock, 1% degrees; slide, % degree. Freedom of guard point 
from edge of table, 1^ degree, when lever Is at rest against its 
bank and escapement is not banked to drop. 

To determine the guard freedom when escapement is "banked 
to drop subtract the slide % degree from the original guard free- 
rom, 114 degrees; this leaves % degree as amount of guard free- 
dom when banked to drop. 

246. Summary of Corner and Guard Freedoms — Elgin Type. — 
Slide Present — Not banked to drop corner freedom, I14 de- 
grees; not banked to drop guard freedom, li^ degrees. 

Slide Absent — When banked to drop corner freedom, % de- 
grees; when banked to drop guard freedom, % degrees. 

The lesson to be learned from above is, that an Elgin type 
of escapement when lanked to drop shows toth guard and corner 
freedoms. 



69 

When slide is present the freedoms are increased by exactly 
the amount of slide. Compare with No. 249. 

To protect the safety locks, the drop lock in an Elgin type 
of escapement always exceeds the corner and guard freedoms. 

247. Slide and Corner Freedom — South Bend Type. — Specifi- 
«ations — Total lock, 2 degrees. The total lock is made up of: 
Drop lock, 1 degree, and slide, 1 degree. Freedom of slot corner 
from roller jewel, lever against its bank, 1 degree. 

According to the foregoing figures, a South Bend type of 
escapement possesses a corner freedom of the same amount as 
the slide. Therefore, when not banked to drop, we find the same 
amount of slide and corner freedom. 

When this escapement is danked to drop we of course thereby 
destroy the slide. As the amount of slide equals the amount of 
corner freedom, no corner freedom will be found when banked to 
drop. 

248. Slide and Guard Freedom — South Bend Type. — Specifi- 
cations — Total lock, 2 degrees; of this amount, 1 degree will 
represent drop lock and 1 degree slide. The freedom of the guard 
point from edge of table, lever against bank is to be 1 degree. 

The specifications given show, that a South Bend type of 
escapement possesses slide equal in amount to guard freedom. 
By banking this escapement to drop we remove both slide and 
guard freedom. 

249. Summary Corner and Guard Freedoms — South Bend 
Types. — 

Slide Present — Not banked to drop corner freedom, 1 degree; 
not banked to drop guard freedom, 1 degree. 

Slide Absent — When banked to drop corner freedom, none; 
when banked to drop guard freedom, none. 

As shown by the summary when slide is present, both guard 
and corner freedom are present. When slide is absent in a South 
Bend type of escapement the freedoms are likewise absent. See 
No. 246 for comparison. 



70 



LESSON 24 



THEORY AND EXPLANATION OF THE ANGU- 
LAR TEST—ELGIN TYPE 



250. Uses of the Angular Test. — The angular test Is of all 
tests the most accurate for determining if an escapement is either 
in or out of angle. It is the dominant test for yielding informa- 
tion relative to the action of the roller jewel as it relates to the 
fork. It expresses as no other test can or does the close associa- 
tion which exists between the lock (drop lock) and the length of 
the lever. We shall state the principles governing the test, 
making use of specifications for this purpose. 

251. Specifications. — Escapement banked to drop, Elgin type: 
Drop-lock, 1% degrees; lift on tooth, 3 degrees; lift on pallet, 5^^ 
degrees ; freedom of the roller jewel from the slot corner, 1 degree 
(banked to drop). 

By adding the drop-lock and both of the lifts together we 
obtain the lever's angular motion from bank to bank as 10 degrees. 
If we have an escapement built in conformity yith the above 
specifications, the same being banked to drop, we would on using 
the angular test learn what is meant by the correct relationship 
of the roller jewel-fork action to the tooth and pallet action. In 
other words, the angular test will decisively inform us if the 
parts are well matched. We can also with exceptional accuracy 
determine if an escapement is in or out of angle. 

252. Preliminary Explanation of the Angular Test — Elgin 
Type. — In accordance with instructions supplied in a later lesson 
on the angular test we assume that the motion of the lever is 
blocked, viz., wedged. Then, by placing a finger on the balance 
rim, cause the balance to rotate, thereby bringing the roller 
jewel into the slot. This rotation is continued until the roller 
jewel pushes its way past the slot corner. If we then make an 
examination of the escapement parts two facts will be noticed: 
First, the lever fails to reach its bank, although acting under 
banked-to-drop conditions. Secondly, the tooth of the escape 
wheel remains in contact with the pallet jewel after the manner 
shown in Fig. 29. 



71 

253. Theoretical Explanation of the Angular Test — Elgin 
Type, — Why the lever failed to reach its bank and why the tooth 
remained in contact with the pallet jewel is best explained by 
means of the specifications. The specifications (banked to drop) 
call for 1 degree of freedom between the roller jewel and the 
corner of the slot when the lever is at rest against its bank. Under 
test conditions (lever wedged) the space we see separating the 
side of the lever from the banking pin is the equivalent of the 
stated freedom of the roller jewel, from the slot corner as given 
in the specifications. This amounts to 1 degree. The lever there- 
fore fails to reach the opposite bank by 1 degree of angular 
motion. 

We figured in the specifications that the lever's angular 
motion from bank to bank equals 10 degrees. The contact of 
the roller jewel with the fork slot amounts to 9 degrees (10° — 
1° = 9°). Therefore 9 degrees represents the actual amount 
traveled by the lever. As it takes 10 degrees of angular motion 
to release a tooth from the pallet, it can now be plainly under- 
stood why the tooth (lever wedged) must remain in contact with 




C oTr2(?t' 



Fig. 29 

the pallet jewel, as illustrated in Pig. 29. The facts above stated 
apply to all escapements of the Elgin type, irrespective of their 
specifications. 

254. Summary of Angular Test Findings — Elgin Type. — 
These facts we shall now briefly repeat. An escapement of the 
Elgin type when the parts involved are correctly matched will 
show by the angular test: 

A. That the lever is unatle to reach its opposite bank. 

B. That the teeth of the escape wheel will remain in contact 
with the pallet jewel's, as shown in Fig. 29. 



72 



LESSON 25 



THEORY AND EXPLANATION OF THE ANGU- 
LAR TEST— SOUTH BEND TYPE 



255. Specifications — Angular Test — South Bend Types. — Drop 
lock, 1 degree; lift on pallet, 4i^ degrees; lift on tooth, 3% 
degrees. 

The lever's angular motion is the sum of the above, viz., 9 
degrees. 

The above specifications indicate, because of the absence of 
slide, that the escapement is banked to drop. 

256. Theoretical Explanation of the Angular Test — South 
Bend Type. — The lever's angular motion is composed of the drop- 
lock, the lift on the tooth and the lift on the pallet; their total 
equals 9 degrees. As there is no provision in the specifications 
for the freedom of the roller jewel from the slot corners (corner 
freedom) under 'banTced-to-drop conditions, we must therefore 
expect to find contact of the roller jewel with the fork slot during 
the lever's motion from bank to bank when subjected to the 
angular test. To avoid confusing beginners we wish to point 
out that when the bankings are opened for slide the necessary 
corner freedom is thereby provided. 

257. Summary of Angular Test Findings — BanTced to Drop — 
South Bend Type. — Given an escapement constructed according 
to the specifications before stated, it will be found that when 
the angular test is used and the escapement is banked to drop 
the following takes place: 

A — The roller jewel will touch the slot corners either passing 
in or out of the slot. 

B — The lever will move from one bank to a position of contact 
with the opposite bank. 

C — The escape-wheel teeth will be discharged from each pallet 
jewel. 

These findings are contrary to the proof findings of an Elgin 
type of escapement. The difference between the types must be 
remembered. 



73 



LESSON 26 



THE ANGULAR TEST IN PRACTICE— VARIA- 
TIONS, AND OUT OF ANGLE 



258. How to Apply the Angular Test. — Commence by banking 
the escapement to drop. The escapement being banked to 
drop, place a wedge under the lever. The material used for a 
wedge varies with the accessibility of the lever. For use in full 
plate watches the wedge can be made from a piece of very weak 
and narrow mainspring. The piece selected should be about 
one inch in length. For convenience and practical reasons form 
the wedge into the shape of a bow. This bow-shaped wedge is 
especially useful in full plate watches. When inserted under 
the lever it acts as a spring cushion in retarding the lever's 
motion. The suggested steel wedge cannot be used in all watches 
owing to recesses in plate, in which event cork or pith can be 
employed. Having the lever wedged and the balance in position, 
place a finger on the balance rim and start revolving same, 
thereby bringing the roller jewel into the slot and out the 
opposite side. As a matter of precaution it is wise to cease turning 
the balance, when in passing out, the center of the roller jewel 
comes opposite the slot corner. This is advised to avoid any 
©hance of the guard-point engaging the edge of the roller and 
thereby falsely increasing the lever's motion. The roller jewel 
being moved into the desired position, remove the finger from the 
balance, then with an eye-glass observe the relation of the tooth 
and pallet jewel. If the lock is correct and the lever's acting 
length likewise correct the tooth will be found barely m contact 
with the releasing corner of the pallet jewel, as shown in Fig. 
29. A test on the opposite side should reveal like contact of 
tooth and pallet. When the contact of each tooth with its pallet 
jewel resembles Fig. 29 we know that the parts involved are well 
matched and the escapement correct from the standpoint of the 
angular test's proof-findings. Proof-findings when discovered 
teach us that the roller jewel's action with the fork is exactly 
adapted to the drop lock. The angular test will at times show 
tooth and pallet conditions not in conformity with the proof- 
findings. When irregular conditions are found, examine the 



74 

nature and extent of drop-lock and make use of the corner test 
to assist in uncovering the cause of error. The proof-findings 
above mentioned refer only to an Elgin type of escapement. 

259. The Guard-Point and the Angular Test. — ^When using 
the angular test it is advisable to remove the guard-point from 
proximity to the roller. Should the guard-point be too close to 
the roller it may, when the lever is wedged, touch the roller's 
edge, thereby causing an increased motion of the lever. This 
motion would alter the position of the tooth with relation to its 
pallet. This would lead to an erroneous decision. 

260. Blocking the Lever — Angular Test. — Blocking the lever's 
motion is a quick way of applying the angular test. Its use is 
not advisable for beginners, because some previous experience by 
the slower method of wedging is necessary to prevent erroneous 
deductions. Blocking the lever possesses this advantage: An 
escapement can be examined in its original condition, namely, 
with the guard-pin straight and slide present. Should errors be 
discovered, then, to make certain the guard-point must be re- 
moved from the edge of the roller and a retest made. The 
following is the routine: 

First — With the lever at rest against its bank. 

Second — Take a watch oiler and press it against the side of 
the lever, apparently with the intention of retaining the lever 
against its bank. 

Third — Place a finger on the balance and guide the roller 
jev/el into the slot. 

Fourth — Hold the tool against the side of the lever and cause 
the roller jewel to push the lever toward the opposite bank. 

Fifth — Keep turning the balance until the roller jewel is 
"felt" to just emerge from the slot. 

Sixth — Carefully retain the tool against the side of the lever 
in the exact position it occupied when the roller jewel — see No. b 
— started to scrape its way past the slot corner and examine the 
relation of tooth and pallet. 

2G1. Variations from Proof Findings of the Angular Test. — 
In actual bench practice many variations from the standard 
proof findings will be encountered. For instance a tooth on one 
pallet may show more contact than another tooth on the opposite 
pallet; or one tooth may remain in contact, the other tooth being 
discharged, etc. Conditions departing from normal proof findings 
express the fact that some escapement error is present. Begin- 
ners in escapement testing should learn to locate the error by 
means of banking to drop the guard, corner and safety tests. 
Knowing these, no trouble will be experienced in reading depar- 
tures from the proof findings. We know from actual experience 
with young watchmakers that, given a knowledge of the nature 
of lock, banking to drop, corner, guard and safety tests, they can 



75 

successfully attempt escapement alterations. Especially so when 
alterations are checked by the proof findings of the angular test. 

262. Out of Angle, as Shown dy the Angular Test — Elgin 
Type, — As previously mentioned, the proof findings of an Elgin 
type of escapement will show similar points of contact of each 
tooth with its pallet jewel. Out of angle conditions are expressed 
as follows: 

A. Any departure from corresponding positions of contact 
declares the escapement as out of angle. 

B. If the amount of contact of one tooth with its pallet jewel 
exceeds the amount of contact shown by the tooth on the opposite 
pallet the escapement is out of angle. 

C. When one tooth remains in contact and the other tooth is 
discharged from its pallet jewel the escapement is out of angle. 

263. Causes Producing Out of Angle. — 

A. The most frequent cause of an escapement being out of 
angle is due to irregularities in the drop locks; that is, the 
drop lock on one pallet differs in extent from the drop lock 
on the opposite pallet. Of course equalizing the drop locks cor- 
rects "out of angle." 

B. Out of angle is sometimes attributable to the lever being 
bent. 

C. A bent lever and inequalities of the drop locks combined 
may also cause an escapement to be out of angle. Whatever 
the source of this error may be, it generally requires correction. 

264. Out of Angle — South Bend Escapement Types and the 
Angular Test. — When testing to learn if an escapement of the 
South Bend type is out of angle, do not bank the escapement to 
drop. Theoretical explanations already given, together with 
practical experiments will establish the reason for this state- 
ment. Prior to investigating the subject of out of angle in escape- 
ments of the South Bend type, students should become familiar 
with "out of angle" as found in escapements of the Elgin class. 
No trouble will then be experienced in detecting "out of angle" in 
South Bend escapements. 



76 



LESSON 27 



DROP LOCK— ITS VARIATION 



265. Drop Loch — As the Watchmaker Finds It. — ^That the 
expression ''correct drop lock" means drop lock of varying quan- 
tity is a fact apparent to every practical watchmaker. A drop 
lock that is suited to a watch of high grade would be unsuitable 

for a low-grade watch. This statement is not made from a 
theoretical viewpoint, but from the standpoint of the man at 
the bench. Writers have a habit of ignoring all conditions of 

lock save one — that is, drop lock in its theoretical form. Never- 
theless the repairer is constantly encountering forms of drop 
lock differing widely from the theoretical variety. Tne watch- 
maker in his daily work meets with escapements as they are — 
practical — and rarely as they ought to be — theoretical. This 
Intermixture of escapement construction is puzzling until read in 
the light of the angular test. 

266. Three Types of Escapements. — The man at the bench 
encounters three types of escapement perfection. Each in its way 
gives satisfaction, because the associated parts are well matched 
and therefore suited to each other. First, we have the perfect 
escapement, which is rather rare; second, the correct escapement, 
frequently found in high-grade watches; third, the more common 
and plentiful type — namely, the commercially correct escapement. 
The governing feature of each escapement type is that the parts 
are well matched. The parts of the perfect escapement are 
matched theoretically and practically, consequently an exact 
barmony of action prevails. 

In the correct escapement the parts are also well matched, 
but at the expense of an increased frictional resistance. 

The parts of the commercially correct escapement are like- 
wise matched, a fact capable of proof by the angular and other tests. 

Students must learn to recognize the distinctions named 
and to get away from the misleading idea that many escapements, 
because the parts are matched, are theoretically perfect. The 
investigating student will soon learn that the majority of escape- 
ments are commercially matched, the minority being matched 
theoretically. 



77 

267. Escapement Matching. — By correct or commercial match- 
ing of an escapement we refer particularly to a drop lock exactly 
suited to a given length of lever and roller jewel radius. The 
fact is that in the sense mentioned escapement tests may agre« 
in declaring the parts matched — that is, the drop lock is adapted 
to the action of the roller jewel with the fork. This, however, 
does not imply escapement perfection, as our future lest lessona 
and experiments will prove. 

268. Drop Lock in a Perfect Escapement. — If an escapement 
of the Elgin type possesses a theoretically correct drop lock, ana 
associated with this is a lever whose acting length is theoretically 
correct, the parts are assuredly well matched. The angular test 
will express this fact by showing the correct amount of contact 
of the tooth with the pallet, as illustrated in Fig. 29. This draw- 
ing represents the proof-findings. 

The corner test will also demonstrate that the correct amount 
of corner freedom is present. 

269. Drop Lock in a Correct Escapement. — An escapement of 
this class — Elgin type — possesses a drop lock somewhat greater 
than that found in a theoretical or perfect escapement. When a 
"correct' escapement" possesses a lever whose acting length and 
roller-jewel radius are adapted to the amount of drop lock present 
the angular test will show contact of tooth and pallet as repre- 
sented in Fig. 29. 

The corner test will also show a corner freedom of suitable 
amount. 

In a "correct escapement" we also find there exists a smooth, 
concerted action of the escapement parts as revealed by the tests. 
In other words, the parts are well matched. 

270. Drop Lock in a Commercialy Correct Escapement. — The 
majority of escapements belong to the commercialy matched 
class. Such escapements have a drop lock deeper than that found 
in the "correct escapement" mentioned previously. Associated 
with the greater lock will be a lever or roller-jewel radius of 
increased length, but exactly suited to the increased drop lock. 
When escapements of the "commercially correct" variety are pro- 
vided with either a lever whose acting length matches the drop 
lock or a roller jewel whose radius corresponds with this lock 
the angular test will show tooth and pallet contact as illustrated 
in Fig. 29. 

The corner test will show the escapement as provided with a 
corner freedom exactly suited to its condition, but exceeding In 
amount the corner freedoms of the two preceding types. 

That the parts are matched is as much in evidence in the 
"commercial" as in the higher escapement types. 

It should be the aim of every watchmaker to at least change 
the more commercial products into a more perfect type of escape- 



78 

ment. Usually the change can be made with but little trouble 
once the primary principles of the locks and tests have been 
mastered. 

At first it is advisable for students to confine their studies 
and experiments to the Elgin type. Dueber and South Bend 
escapements will afterward present no difficulties. 



79 



LESSON 28 



BANKING TO DROP IN PRACTICE 



271. Findings — Banked to drop. — The student ambitious to 
advance must experiment with escapements tanked to drop. The 
findings stated below will be met with in all watches when the 
parts are well matched. These test findings represent the proof 
or correct findings — banked to drop — for escapements of the Elgin 
and South Bend types. A few practical experiments will show 
that many departures from our test standards prevail, the irregu- 
larities being due to escapement faults. Full instruction regard- 
ing the detection and correction of errors will be found in the 
pages covered by the "Test Lessons." 

A study of these lessons will lead the student out of various 
escapement difiiculties. 

272. Banked to Drop Findings (Elgin Type — Parts 
Matched). — 

Guard Test — A slight freedom between the guard point and 
roller — guard freedom. (See drawing No. 24.) 

Corner Test — A slight freedom between the slot corners and 
roller jewel — corner freedom. (See Fig. 26.) 

Angular Test — Each tooth shows contact with its pallet jewel 
as illustrated in Fig. 29. 

Contrast the above Elgin findings with the following, repre- 
senting findings iu the South Bend type. Then by practical ex- 
perim,ents impress on your memory the ever-useful and important 
truths stated in this and the following paragraph. 

273. Banked to Drop Findings (South Bend Type — Parts 
Matched). — 

Guard Test — No freedom between the guard point and roller 
table. 

Corner Test — No freedom between the slot corners and the 
roller jewel. 

Angular Test — No contact of tooth and pallet, as illustrated 
in Fig. 30. 



80 



LESSON 29 



TYPES OF AMERICAN ESCAPEMENTS 



274. American Escapement Types. — Two different types of 
escapements are found in American-made watches. For con- 
venience we have designated them Elgin and South Bend. The 
term "Elgin type" applies to all makes, excepting South Bend and 
Dueber, the latter being associate escapement types. The differ- 
ence in type is extreme as viewed from the standpoint of our 
tests, a fact readily discovered by comparing the banked-to-drop 
test findings of each type as already set forth in Lesson 28. 

275. Lock Division of the Elgin Type. — Of the total lock in an 
escapement of the Elgin type — in round numbers — practically 
two-thirds represent the drop lock, the remaining one-third being 
slide. 

276. Lock Division of the South Bend Type. — The total lock 
in an escapement of the South Bend type is equally divided — viz., 
one-half represents the drop lock, the other half is slide. 

Note on Foreign Escapements — ^As a general rule, examine 
a foreign-built escapement as you would an Elgin. While this may 
not be an invariable rule, yet, so far as the writer knows, the 
Elgin is the most applicable type for this purpose. 



81 



LESSON 30 



ESCAPEMENT EXAMINATION 



277. Preliminary Advice. — The tests stated in the lessons are 
accurate and reliable, because they are founded upon both a 
theoretical and practical basis. No matter how accurate tests 
may be, mistaken deductions will be made unless the below 
instructions are closely followed out. 

278. General Preparatory Instructions. — 

(a) See that all hole jewels are tight in their settings, and 
that jewel settings are tight in their seats. 

(b) See that all pivots correctly fit their respective holes. 
Should defects in fitting be discovered, make the necessary 
corrections. 

(c) Attend to the end shakes of all parts. 

(d) The hair spring requires to be true, level, and correctly 
centered. Free from the balance arm and bridge, and tightly 
pinned at collet and stud. 

(e) The banking pins must be tight and upright. 

(f) The guard point must be tight and correct in shape. 

(g) See that the lever and its attached parts are secure, 
(h) The roller table should be true in flat and round. Tight 

on staff and with smooth edges. 

(i) The condition of "draw" must be investigated. 

(j) The extent of each drop lock requires to be known. An 
estimate of the degrees of each lock should be made. 

(k) The number of degrees of slide should likewise be 
known. 

(1) The inside and outside drop should be examined, and, if 
necessary, the extent of the drop in degrees determined. 

(m) Shake, "inside and out," calls for careful examination. 

(n) Examine the lifts of tooth and pallet. Especially observe 
their manner of engaging and disengaging. 

(o) Determine amounts of "guard freedom," banked and not 
banked to drop. 

(p) Investigate the condition of the "corner freedoms," 
banked and not banked to drop. 



(q) Employ the safety tests to try out all the safety locks. 

(r) Make use of the angular test and learn If the parts are 
matched or otherwise. 

279. Routine Escapement Examination. — The following is a 
short outline of an escapement examination: 

First — Bank the escapement to drop. 

Second — Inspect the drop lock. 

Third — Inspect the inside and outside drops. 

Fourth — Inspect the shakes inside and out. 

Fifth — Inspect the draw on both pallets. 

Sixth — ^As a precautionary measure remove the guard point 
from the edge of the roller — that is, increase the distance which 
normally separates these parts. 

Seventh — Try the corner test. 

Eighth — Try the corner safety test. 

Ninth — Make use of the angular test. 

(Here we pause to make the necessary alterations in accord- 
ance with directions given in the "Test Lessons.") 

Tenth — Readjust the guard point to the roller. 

Eleventh — Try the guard test. 

Twelfth — Try the guard safety test. 

As the student becomes familiar with escapement work 
and the tests the routine of examination can be much shortened, 
as shown by our "Bench Problems," examples being given in later 
lessons. 



83 



LESSON 31 



SUMMARY OF THE TESTS 



280. Divisions of Tests. — The division and subdivision 
of the tests as gathered together in this lesson are given in a 
form convenient for reference and bench usage. The tests for 
freedoms in the Elgin type hanked to drop are, respectively, the 
guard test, the corner test and the curve test. 

The subdivisions of these tests are the guard safety test, 
the corner safety test, and the curve safety test. Their distinc- 
tion, difference and application must be grasped by every student. 
The best way to learn the tests is the practical way — namely, 
with a watch in hand. The angular test is not included in this 
summary, full details having been given in a preceding lesson. 

281. Testing the Draw. — 
First — Remove the balance. 

Second — Lift the lever off its bank with a piece of pegwood, 
but not sufficient to cause unlocking. 

Third — Remove pegwood. 

Fourth — If the draw is sound the lever immediately returns 
to its bank. If the escapement is freshly oiled and clean and 
the draw on either pallet proves defective a correction is neces- 
sary. (See Test Lessons on Draw.) 

282. Testing the Lock. — The locks should be tested both by 
observation and the angular test. Should either the drop lock or 
the slide lock be found defective a correction is necessary. When 
in doubt about the extent of drop lock bank the escapement to 
drop, then retest. 

An estimate of the amount of drop lock, in degrees, can be 
made by aid of the tables given in paragraph No. 180. 

Note. — ^When the locks are tested, the student is advised 
to carefully/ observe the "lifts," as directed in Lesson 11. 

283. Testing the Inside Drop. — 

First — To make this test students are advised to bank the 
escapement to drop. When experience is gained this is not 
necessary. 



84 

Second — Cause a tooth to be discharged from the letting-off 
corner of the entering pallet and note the amount of its drop. 
(See Lesson 13, paragraph No. 184.) 

284. Testing the Outside Drop.— 
First — Bank the escapement to drop. 

Second — Cause the discharge of a tooth from the releasing 
corner of the exit pallet and observe the extent of drop. (Consult 
Lesson 13, Table of Drops, paragraph No. 184.) 

Inside and outside drop should be equal. The degrees of 
drop can be estimated as explained in Lesson 13. 

285. Testing the Inside Shake. — 

First — Under the lever bar place a wedge of tissue paper. 

Second — ^Allow a tooth to drop on the locking face of the 
exit pallet jewel. 

Third — Bring the tooth at rest on the exit pallet's locking 
face down to the lowest locking corner of this pallet. 

Fourth — Note the space separating the hack of the receiving 
pallet from the heel of the tooth just behind it. The space ob- 
served between the back of the pallet and heel of the tooth is the 
inside shake. 

286. Testing the Outside Shake. — 

First — Place a wedge under the lever bar. 

Second — ^Allow a tooth to drop on the locking face of the 
receiving pallet stone. 

Third — Move the lever so as to bring the tooth at rest on the 
locking face of the receiving pallet down to the pallet's lowest 
locking corner. 

Fourth — Then observe the space separating the hack of the 
exit pallet from the heel of the tooth just behind it. This space 
is the outside shake, and is the position of least freedom of the 
parts concerned. The inside shake and outside shake should be 
equal. 

287. Testing the Freedom of the Roller Jewel in the Slot.— 
First — Place a wedge under the balance rim. 

Second — Rotate the balance so that the roller jewel stands 
centrally in the slot; the lever will then stand midway between 
the bankings. 

Third — With the aid of a tool find out, by shaking the lever, 
how much side play the roller jewel has when within the slot. 

288. Guard Test Findings — Single and Douhle Roller. — The 
purpose of the guard test is to learn the relation of the guard 
point to the roller. When an escapement of the Elgin type is 
banked to drop a slight space or guard freedom should be found. 
When a Dueber or South Bend escapement is hanked to drop the 
correct finding by the guard test is that of contact of the guard 
point with the edge of the roller. 



85 

289. Guard Safety Test Findings, Single and Double Roller — 
Tripping Test. — The intention of the guard safety test is to de- 
termine the condition of the safety lock. If the safety or remain- 
ing lock is absent a tripping error is present. This or any of 
the safety tests can be made with or without banking the escape- 
ment to drop. 

METHOD OP MAKING THE GUARD TEST— SINGLE AND 
DOUBLE ROLLER 

290. Guard Test— Elgin Type- 
First — Bank the escapement to drop. 
Second — Lift the lever off its bank. 

Third — The effect of our second operation is to bring the 
guard point in contact with the edge of the roller. 

Fourth — The extent we are able to lift the lever away from 
its bank represents the guard freedom. 

291. Guard Test — South Bend Type. — 
First — Bank the escapement to drop. 

Second — The lever cannot be lifted off its bank because the 
parts under consideration will touch. Consequently the guara 
freedom is and should be absent. 

METHOD OF MAKING THE GUARD SAFETY TEST— SINGLE 
AND DOUBLE ROLLER 

292. Guard Safety Test — Tripping Test. 

First — Bring the guard point in contact with the edge of the 
roller. 

Second — Hold the guard point in contact with the edge of 
the roller. 

Third — ^While the parts are held in touch with each other, 
with an eyeglass observe the extent of the remaining or safety 
lock of the tooth on the pallet jewel's locking face. If there is no 
safety lock the tooth will enter on to the pallet jewel's impulse 
face. This means a tripping error is present. Its cause and 
correction will be found in that part of the book relating to this 
subject. (See Test Lesson on the Guard Safety Test.) 

293. Corner Test Findings — Single and DouMe Roller. — By 
means of the corner test we learn the relation of the slot corners 
to the roller jewel. This should be done with the escapement 
banked to drop. An Elgin type of escapement, when banked to 
drop, will show by the corner test a little freedom — corner free- 
dom — between the slot corner and the roller jewel. A Dueber or 
South Bend escapement when banked to drop shows no freedom 
between the slot corners and the roller jewel. 

294. Corner Safety Test Findings, Single and Double Roller — 
Tripping. — The purpose of the corner safety test is to investigate 



86 

the safety lock. A safety lock is a necessity and, if lacking, must 
be provided as directed in the test lesson. 

METHOD OF MAKING THE CORNER TEST— SINGLE AND 
DOUBLE ROLLER. 

295. Corner Test — Elgin Type. — 
First — Bank the escapement to drop. 

Second — Rotate the balance so as to bring the roller jewel 
opposite the corner of the lever-slot. 

Third — By means of some fine tool lift the lever off its bank, 
thereby causing the slot corner to touch the roller jewel. 

Fourth — The extent we are able to lift the lever from its 
bank represents the amount of corner freedom. 

296. Corner Test — Bouth Bend Type — 
First — Bank to drop. 

Second — The roller jewel when passing in or out of the slot 
will touch the corners. This means corner freedom is not present, 
which finding is correct. 

METHOD OF MAKING THE CORNER SAFETY TEST— SINGLE 
AND DOUBLE ROLLER 

297. Corner Safety Test — Tripping Test. — 

First — Rotate the balance so as to bring the face of the roller 
jewel opposite the corner of the lever slot. 

Second — Hold the roller jewel in the position mentioned 
above. 

Third — ^With a fine tool lift the lever away from its bank, 
thereby causing the corner of the slot to come in contact with the 
roller jewel. 

Fourth — Hold the parts in contact and with an eyeglass; 
inspect amount of the remaining or safety lock. An absence 
of safety lock indicates a tripping error, which must be corrected. 

METHOD OF MAKING THE CURVE TEST— SINGLE AND 
DOUBLE ROLLER 

298. Curve Test — Single Roller — 

First — With a watch oiler or other fine tool hold the guard 
pin against the edge of the roller. 

Second — Rotate the balance, thereby bringing the roller jewel 
past the horn and into the slot. 

Third — While roller jewel is passing the horn, contact being 
maintained, no contact of the upper part of the horn with the 
roller jewel should be detected. 

Fourth — Immediately the guard pin enters the crescent the 
roller jewel and horn will come in contact. A slight friction of 
the roller jewel with a small part of the horn and with the slot 



87 

corner will be detected, but nothing resembling a catch is allow- 
able. The extent of the horn with which the roller jewel under 
test conditions can come into contact depends upon the width of 
the crescent. 

299. Curve Safety Test, Single Roller — Tripping Test. — As 
mentioned in the curve test, once the guard pin enters the cres- 
cent a small part of the horn can be brought into contact with 
the roller jewel. Immediately this happens retain the parts in 
contact and examine the condition of the safety lock. As a matter 
of fact, the curve safety test is of little importance in single- 
roller escapements. In double-roller escapements it is a very 
important test. 

300. Curve Test—Douhle Roller.— 

First — Lift the lever away from its bank, thereby we bring 
the guard finger and roller jewel in contact. 

Second — Maintain the parts in contact and revolve the bal- 
ance, so as to bring the roller jewel past the end of the lever 
horn and in the direction of the slot. 

Third — Continue to slowly revolve the balance, at the same 
time keeping the guard finger pressed against the table's edge. 
The instant the guard finger enters the crescent, the roller jewel 
and curve of horn come into contact. This contact continues 
until the roller jewel enters the slot. The roller jewel should 
slide over the face of the horn and into the slot without develop- 
ing any undue friction. 

301. Curve Safety Test, Double Roller — Tripping Test. — ^The 
fourth section of the foregoing test says, "Immediately the guard 
pin enters the crescent the roller jewel and horn will come in 
contact." When the parts stand in the position quoted, then to 
examine the safety lock hold the horn and roller jewel in touch 
with each other while the extent of the remaining or safety lock 
is investigated. A want of safety lock means a tripping error. 
This fault must be corrected and alterations made in accordance 
with the directions given in that part of the book treating on 
Bench Problems and Test Lessons. Students who do not quite 
understand any particular point or subject will find the series 
of "Questions" a most useful feature. 

BUTTING ERROR 
301 A. Test for Butting Error. — The student is referred to 
Lesson 58. 



88 



LESSON 32 



CLASSIFYING DROP LOCK— CORNER FREE- 
DOM AND GUARD FREEDOM 



302. Drop Loch Classification. — In the test lessons drop lock 
is classified into its three main forms, namely (see 265), correct, 
light and deep. 

To classify the amount of drop lock as correct, light or deep, 
for any given escapement, combinedly requires the employment 
of the angular test, and an estimate of the extent of lock as 
directed in paragraph No. 183. Lesson 27 should also be con- 
sulted. 

303. Corner Freedom Classification. — Corner freedom, when 
the escapement is of the Elgin type and banked to drop, is 
divided into correct freedom, excessive and contact gr no freedom. 

The "Test Lessons" specify the corner freedom for an Elgin 
type of escapement when banked to drop, as correct, excessive, 
or wanting. Of the three, the most important to learn to recognize 
is that which we have designated "correct freedom." This, like 
its intimate associate, "correct lock," is a varying quantity. The 
correct amount of corner freedom as found in high-grade watches 
differs (from the standpoint of the man at the bench) from the 
correct amount of corner freedom associated with low-grade 
watches; yet each in its place is correct for that escapement of 
which it is a part. An observation and estimation of the extent 
of drop lock, and a few experiments with the corner and angular 
tests will place the student in a position to classify the freedoms. 

304. Guard Freedom Classification. — In an Elgin type of 
escapement, when banked to drop, the guard freedom will be 
found as follows: Correct, excessive, or wanting. One of the 
three distinctions will describe conditions present: 

Correct guard freedom, like its predecessors, correct lock and 
correct corner freedom, varies with the grade of escapement. 
Correct guard freedom, as discovered in a low-grade watch, would 
be unsuited to a high-grade escapement. 

The term correct guard freedom is and will be found elastic. 
In quantity it should about equal the corner freedom. Its extent 
should not endanger the safety lock nor cause a butting error. 



89 

305. Classification as Used in the Test Lessons. — Regarding 
the "Test Lessons," in the following pages, the observed routine 
is that of treating and discussing one error, and teaching the 
relationship of this error to three different kinds of drop lock, 
viz.: Correct, light, and deep. 

As an example of method pursued, Test Lesson 3 A treats on 
the error of excessive corner freedom when associated with 
correct drop lock. 

Test Lesson 3 B likewise treats on the error of excessive 
corner freedom, including the added error of light drop lock. 

Test Lesson 3 C again discusses the error of an excess of 
corner freedom combined with the error of deep lock. 

In this manner the test lessons are linked together and 
prominent escapement truths are plainly set before the student. 



90 



LESSON 33 



RULES GOVERNING ALTERATIONS 



306. Advice and Remarks. — The student must acquire a 
thorough knowledge of the general effects caused by any con- 
templated escapement alteration. For instance, making the drop 
locks deeper will produce the "effects" mentioned in Rule 1. In 
a practical way study and work out each rule. By doing so you 
will find it an easy matter to forecast the result of an alteration. 
Don't neglect the Questions on Rules and Alterations. They will 
be found helpful in impressing the practical facts contained in 
the rules. 

Students should at first confine their practical experiments 
to escapements of the Elgin type, always keeping same hanked 
to drop. 

Once you become familiar with the principles governing 
alterations in this type, no trouble will be experienced in adapt- 
ing the information to escapements of the South Bend type. 

Young watchmakers, when undirected or but poorly in- 
structed, find the escapement a hard road to travel. Such will 
find the Tests, Rules and Test Lessons lamps on the road to 
practical efficiency. Its "up to you," watchmaker or student, by 
reading and practical experiment, to get out of the rut. 

Experienced workmen desiring only a knowledge of the tests, 
etc., are referred to the following paragraphs: 265 to 301; 379 
to 384; 209 to 264; 306 to 323. 



91 



Index to Rules 



307. Index to Rules. — 



Rule 


1. 


Rule 


2. 


Rule 


3. 


Rule 


4. 


Rule 


5. 


Rule 


6. 


Rule 


7. 


Rule 


8. 


Rule 


9. 


Rule 


10. 


Rule 


11. 


Rule 


12. 


Rule 


13. 


Rule 


14. 


Rule 


15. 


Rule 16. 


Rule 


17. 


Rule 


18. 


Rule 


19. 



Increasing Drop Lock, Effect of. 

Decreasing Drop Lock, Effect of. 

Increasing Corner Freedom, Effect of. 

Decreasing Corner Freedom, Effect of. 

Increasing Guard Freedom, Effect of. 

Decreasing Guard Freedom, Effect of. 

Increasing Lever's Acting Length, or Roller 
Jewel Radius, Effect of. 

Decreasing Lever's Acting Length, or Roller 
Jewel Radius, Effect of. 

Spreading the Bankings Apart. 

Closing the Banking Pins. 

Banked to Drop, Elgin. 

Banked to Drop, South Bend. 

Guard Point Butting Table. 

Corner Freedom and Drop Lock, Both De- 
fective. 

Guard Freedom and Drop Lock, Both De- 
fective. 

Protection of the Safety Lock. 

Out of Angle — Angular Test. 

Out of Angle — Corner Test. 

Out of Angle — Guard Test. 



General Rules 



RULE 1. 

308. Increasing Drop Lock — 

Altebation — Making the drop locks deeper causes the 

following: 
Effect A — The bankings are spread further apart. 

(Banked to drop.) 
Effect B — Increases the guard freedoms. 
Effect C — Increases the corner freedoms. 
Effect D — Increases safety locks. 
Effect E — ^Alters both drop and shake. (See below.) 

Notes on Rule 1 
Receiving Pallet Jewel 
Alteration — Drawing out only the receiving stone. 
First Effect — Increases drop lock on receiving stone. 
Second Effect — Increases drop lock on discharging stone. 
Third Effect — Increases inside drop. 
Fourth Effect — Increases inside shake. 

Dicharging Pallet Jewel 
Alteration — Drawing out only the discharging stone. 
First Effect — Increases drop lock on discharging stone. 
Second Effect — Increases drop lock on receiving stone. 
Third Effect — Increases outside drop. 
Fourth Effect — Increases outside shake. 

RULE 2 

309. Decreasing Drop Lock. — 

Alteration — Making the drop locks lighter produces the 
following effects: 



93 

Effect A — The bankings are brought closer together. 

(Banked to drop.) 
Effect B — Decreases the guard freedoms. 
Effect C — Decreases the corner freedoms. 
Effect D — Decreases safety lock. 
Effect E — ^Alters both drop and shake. (See below.) 

Notes on Rule 2 
Receiving Pallet Jewel 
Alteration — Pushing l}ack receiving stone only. 
First Effect — Decreases drop lock on receiving stone. 
Second Effect — Decreases drop lock on discharging stone. 
Third Effect — Decreases inside drop. 
Fourth Effect — Decreases inside shake. 

Discharging Pallet Jewel 
Altebation — Pushing dacTc discharging stone only. 
First Effect — Decreases drop lock on discharging stone. 
Second Effect — Decreases drop lock on receiving stone. 
Third Effect — Decreases outside drop. 
Fourth Effect — Decreases outside shake. 

RULE 3 

310. Increasing Corner Freedom. — 

Alteration No. 1 — Decreasing the lever's acting length, 

or roller jewel radius. 
Effect A — Increases the corner freedoms. 
Effect B — Decreases the corner safety locks. 
Alteration No. 2 — Increasing the drop lock. 
Effect A — Causes the bankings to be spread apart. 

(Banked to drop.) 
Effect B — Increases the corner freedom. 
Effect C — Increases the corner safety locks. 

RULE 4 

311. Decreasing Corner Freedom. 

Alteration No. 1 — Increasing the levers' acting length, 

or roller jewel radius. 
Effect A — Lessens the corner freedoms. 
Effect B — Increases the corner safety locks. 
Alteration No. 2 — Lessening the drop locks. 
Effect A — The bankings are brought closer together. 

(Banked to drop.) 
Effect B — Lessens the corner freedoms. 
Effect C — Lessens corner safety lock. 



94 

RULE 5 

312. Increasing Guard Freedom. — 

Alteration No. 1 — Increasing the distance separating 

the guard point from tahle. 
Effect A— Increases the guard freedoms. 
Effect B — Decreases the safety locks. 
Effect C — May result in causing either a butting or 

overbanking error. 
Alteration No. 2 — Making each drop loch deeper. 
Effect A — The bankings are spread apart. (Banked to 

drop.) 
Effect B — Increases the guard freedoms. 
Effect C — Increases the safety locks. 

RULE 6 

313. Decreasing Guard Freedom. — 

Alteration No. 1 — Lessening the distance 'between guard 

point and table. 
Effect A — Decreases guard freedom. 
Effect B — Increases the safety locks. 
Alteration No. 2 — Decreasing the drop locks. 
Effect A — The bankings are brought closer together. 

(Banked to drop.) 
Effect B — Decreases guard freedoms. 
Effect C — Decreases the safety locks. 

RULE 7 

314. Increasing Levers' Acting Length, or the Roller Jewel 

Radius. — 
Alteration — Making longer, either the lever's acting 

length, or roller jewel radius. 
Effect A — Decreases corner freedoms. 
Effect B — Increases the corner safety locks. 

RULE 8 

315. Shortening Lever's Acting Length, or Roller Jewel 

Radius. — 
Alteration — Decreasing the lever's acting length, or 

radius of roller jewel. 
Effect A — Increases corner freedom. 
Effect B — Decreases the corner safety locks. 

RULE 9 

316. Opening the Banking Pins. — 
Alteration — Spreading the bankings apart. 



95 

Effect A — Increases guard freedom. 
Effect B — Increases corner freedom. 
Effect C — Increases, or provides "slide." 
Effect D — Increases, or provides "run." 

RULE 10 

317. Closing the Banking Pins. — 

Alteration — Bringing the hanking pins closer together. 

Effect A — Lessens guard freedom. 

Effect B — Lessens corner freedom. 

Effect C — Lessens, or removes "slide." 

Effect D — Lessens, or removes "run." 

Effect E — Banks to drop. (No run, no slide.) 

RULE 11 

318. Banked to Drop. — An Elgin type of escapement when 
banked to drop will show the following: 

(a) Some guard freedom. 

(b) Some corner freedom. 

(c) A safety lock less in amount than the drop lock. 

RULE 12 
A South Bend escapement, when banked to drop, will show: 

(d) No guard freedom. 

(e) No corner freedom. 

(f) A safety lock of the same amount as the drop lock. 

RULE 13 

319. Guard Point Butting Tahle. — ^When it is found impos- 
sible to adjust the guard point so as to provide correct guard 
freedom without introducing a butting error, it compels us to 
either lessen the diameter of the original table or supply a 
smaller table. 

Either alteration will, when the guard point is advanced, 
provide correct guard freedom and prevent butting. 

RULE 14 

320. Corner Freedom and Drop Lock, Both Defective. — 
Should the corner freedoms (banked to drop) be excessive or 
deficient, and either defect is associated with errors in the drop 
locks, first correct the locks. If still necessary, rectify any error 
then found in the freedoms, as directed in the Test Lessons and 
Rules. 

RULE 15 

321. Guard Freedom and Drop Lock, Both Defective. — ^When 
the guard freedoms (banked to drop) are either excessive or 



96 

deficient, and the defect present is associated with an error in 
the drop locks, first correct the locks. Then, if a guard freedom 
error still remains, correct it, as instructed in the Test Lessons 
and Rules. 

RULE 16 
322. Protection of the Safety Lock. — The safety lock Is 
guarded by: 

(a) Extent of drop lock. 

(b) Amount of guard freedom. 

(c) Amount of corner freedom. 

(d) In all double roller escapements by central part of lever 
horn and roller jewel. 

Note. — The amount of guard freedom, and the amount of 
corner freedom, also the freedom referred to at D, must in all 
escapements be less than the drop lock. 

S23. Escapements Out of Angle. — Cause of errors: (1) Drop 
locks unequal, or (2) lever bent. 

RULE 17 
Angular Test — ^Any dissimilarity in the position of each 
tooth with its respective pallet jewel indicates the escapement is 
out of angle. 

RULE 18 

Corner Test — Should the corner freedoms be unequal (banked 
to drop) and the roller jewel be straight, the escapement is out 
of angle. 

RULE 19 

Guard Test — Any difference in the guard freedoms expresses 
the fact that the escapement is out of angle, provided the guard 
point is straight and escapement banked to drop. 



97 

Index to Test Lessons 1 A to 6 D 

324. Corner Test. — 

LIST 1 
lA. Proof findings. Elgin type. 

LIST 2 
2 A. Drop locks light. Corner freedoms falsely correct. 

2 B. Drop locks deep. Corner freedoms falsely correct. 

LIST 3 

3 A. Drop locks correct. Corner freedoms excessive. 
3 B. Drop locks light. Corner freedoms excessive. 

3 C. Drop locks deep. Corner freedoms excessive. 

LIST 4 

4 A. Drop locks correct. Corner freedoms lacking. 
4B. Drop locks light. Corner freedoms lacking. 
4C. Drop locks deep. Corner freedoms lacking. 

LIST 5 

5 A. Drop locks correct. Roller jewel retained in slot. 
5 B. Drop locks light. Roller jewel retained in slot. 

5 C. Drop locks deep. Roller jewel retained in slot. 

LIST 6 
Corner Safety Test. 

6 A. Drop locks correct. Corner freedoms correct. Error 

corner trip. 
6 B. Drop locks correct. Corner freedoms excessive. 

Error corner trip. 
6 C. Drop locks light. Corner freedoms correct. Error 

corner trip. 
6 D. Drop locks deep. Corner freedoms excessive. Error 

corner trip. 



98 



LESSON 34 



TEST LESSON NO. i A. CORRECT OR PROOF 
FINDINGS—ELGIN TYPE— BANKED TO DROP 



325. Proof-Findings. — Remarks — An escapement of the Elgin 
type belonging to the correct or commercially correct class will, 
if the parts are well matched, show the following con- 
ditions: 

Drop Lock — The drop or first locks should be equal, light, 
and safe. 

Corner Test — The corner test should show an equal amount 
of freedom betwixt the roller jewel and each slot corner. 

Remarks — The correct amount of corner freedom cannot be 
learned from a book. The student is advised to test many high 
grade escapements and thereby discover what is meant by "corner 
freedom correct." In practice the expression correct corner free- 
dom, like correct lock, is rather elastic; it depends very much on 
the grade of the watch. 

Guard Test — The guard point must have an equal amount 
of freedom on each side of the table. 

Remarks — The term "guard freedom correct," like its fellow 
term, corner freedom correct, is a variable quantity. Our 
remarks on correct corner freedoms are equally applicable to 
correct guard freedoms. 

Curve Test — We should by this test find that the roller jewel 
is free from the tips of the lever horns and can pass into the 
notch without decidedly catching on any part of the horn or 
slot corner. 

Angular Test — The angular test should show that each 
tooth barely remains in contact with each pallet jewel, after the 
manner illustrated in Fig. 29. 

Corner Safety Test — Guard Safety Test — Curve Safety Test. — 
Each of the tests named in our heading, when applied, should 
show a safety or remaining lock. 



99 



LESSON 35 



TEST LESSON NO. 2 A—FALSE CORNER FREE- 
DOM—DROP LOCKS LIGHT— ELGIN 
TYPE— BANKED TO DROP 



326. Corner Test. — Remarks — In a high grade watch, light 
locks are not productive of escapement trouble, for the reason 
that all parts are accurately fitted. 

In a low grade watch, light locks are a frequent source of 
trouble. It is to this class of watch that this lesson applies. 

Condition of Escapement — Drop locks light. Corner free- 
doms apparently correct. Escapement banked to drop. 

Observation Test — By observation we discover that the drop 
locks are unsafely light. 

Corner Test — ^An examination by the corner test reveals an 
apparently correct amount of corner freedom between the roller 
jewel and the slot corners. 

Remarks — From the facts that the locks are unsafely light, 
and the corner freedoms apparently correct, we reason that if 
an increase of the locks is desirable altering the locks will cause 
an increase in the corner freedoms. 

Alterations — ^When changes are necessary commence by in- 
creasing the drop locks, making same deeper. 

Increasing the drop locks means we must spread the bank- 
ings, thereby securing a new position of drop lock. Opening the 
bankings increases the freedom between the roller jewel and slot 
corners. (Corner test.) 

Remarks — ^After altering the locks and changing the position 
of the banking pins the escapement's condition will now read: 

Altered Condition of Escapement. — Drop locks commercially 
correct. Corner freedoms excessive. Banked to drop. 

Remarks — At times, provided no tripping error develops 
(corner safety test), further corrections may not be necessary. 

Should additional alterations be required to correct an 
excess of the corner freedom, the necessary changes may be 
brought about by either supplying a new lever of greater acting 
length, or by replacing the roller table. The new table must 
hold the roller jewel in a more forward position. The plan 
usually followed in the factories is that of changing tables. 
During the progress of alterations apply the corner, corner safety, 
and angular tests. When the proof findings of the tests named 
are obtained, the parts are correctly matched. (See Lesson 34.) 



100 



LESSON 36 



TEST LESSON NO. 2 B— FALSE CORNER FREE- 
DOM—DROP LOCKS DEEP— ELGIN 
TYPE— BANKED TO DROP 



327. Corner Test. — Condition of Escapement— Bto]? locks 
deep. Freedom of roller jewel with slot corners seemingly correct. 
Escapement banked to drop. 

Remarks — In this instance an observation of the locks shows 
them as deep. The corner test when applied indicated an ap- 
parently correct amount of corner freedom between the roller 
jewel and the slot corners. Let us now see the effect of altera- 
tions. 

Alterations — The Locks — ^As deep drop lock is a serious 
defect, we correct it, — ^making it normal. 

The Bankings — Decreasing the drop lock compels us to close 
in the bankings to a new banked to drop position. 

The Corner Test — The corner test now shows that the roller 
jewel is in contact, or very nearly in contact with the slot corners. 
This is the result of decreasing the drop locks and the consequent 
rebanking to drop. 

Remarks — Students should learn to reason out effect of 
changes as indicated in the above alterations. The changes made 
now show the following results: 

Altered Condition of Escapement — Drop locks correct. Free- 
dom wanting between roller jewel and slot corners. Escapement 
banked to drop. 

Remarks — The error shown by the above is a lack of corner 
freedoms. To remedy this either the acting length of the lever 
must be shortened or the radius of the roller jewel decreased. 

Alteration — The corner freedom can be increased by cutting 
away a part of the horns and slot corners. We can also increase 
the corner freedom by changing the position of the roller jewel, 
setting it closer to the center of its table, or by selecting a new 
table having its roller jewel in the desired position. While 
changes are being made, frequently use the corner, corner safety, 
and angular tests to verify correctness of alterations. 



101 



LESSON 37 



TEST LESSON NO. 3 A—EXCESSIVE CORNER 
FREEDOM— DROP LOCKS CORRECT- 
ELGIN TYPE— BANKED TO DROP 



328. Corner Test. — Condition of Escapement — Droiy locks 
correct. Excessive freedom of roller jewel with slot corners. 
Banked to drop. 

Remarks — With an eyeglass we inspect the drop locks and 
find they are correct. The corner test in this instance shows 
excessive freedom between the slot corners and the roller jewel. 

The drop locks being correct, require no alteration, but we 
are confronted with this defect — ^when the escapement is banked 
to drop the corner test reveals a great deal of space betwen the 
roller jewel and the slot corners. 

Alterations. — The Locks — The drop locks being correct, do 
not require changing. 

Remarks — ^As the drop locks are satisfactory, we must, to 
correct the excessive corner freedom, either increase the lever's 
acting length, or bring the roller jewel more forward, or we can 
combine both methods. 

The Lever and the Roller Jewel — In the better class of 
watches it is advisable to either advance the position of the roller 
Jewel, or select a new table, one having the roller jewel in a more 
advanced position. Either operation is easier than the fitting 
of a new and longer lever. If the watch is of very low grade 
and possesses a soft lever the walls of the slot can be stretched, 
thereby increasing the lever's acting length. By so doing, the 
excess of space found between the slot corners and the roller 
jewel can be diminished. 

Remarks — From a practical standpoint a slight excess of 
corner freedom need not be regarded as detrimental. Excessive 
corner freedom must be altered whenever the corner safety test 
decides that the safety or remaining lock is endangered. An 
examination by the student of a large number of escapements 
will prove that exactness in corner freedom is frequently lacking. 
While alterations are in progress apply the corner, corner safety, 
and angular tests. 



102 



LESSON 38 



TEST LESSON NO. 3 B— EXCESSIVE CORNER 

FREEDOM— DROP LOCKS LIGHT— ELGIN 

TYPE— BANKED TO DROP 



329. Corner Test. — Condition of Escapement — Drop lock ligM. 
Excessive freedom between the slot corners and roller jewel. 
Banked to drop. 

Remarks — An inspection of the drop locks In this escape- 
ment reveals them as being light. The corner test shows a surplus 
of freedom between the roller jewel and the slot corners. We 
have here two defects requiring attention. 

Alterations — The Lochs — The rule is when the drop locks are 
defective correct them first. In conformity with this rule we 
alter the locks, making them deeper and at the same time 
correct. 

The Bankings — Increasing the amount of the drop locks 
means we draw the pallet jewels further out of their settings. 
This compels us to open the bankings and establish a new posi- 
tion of drop lock. 

The Lever — The act of increasing the locks caused us to 
spread the bankings more apart. The result is, we have increased 
the previous error of excessive corner freedom. The corner 
freedoms now being greater than before the locks were altered, 
the escapement condition is therefore as follows: 

Altered Condition of Escapement — Drop locks correct. Corner 
freedoms have become more excessive. Banked to drop. 

Remarks — To correct the error of excessive corner freedom 
compels us to either increase the lever's acting length, or in- 
crease the roller jewel radius. Follow the instructions already 
given and make constant use of the corner, corner safety, and 
angular tests while changing the escapement parts. (See Les- 
son 37.) 



103 



LESSON 39 



TEST LESSON NO. 3 C— EXCESSIVE CORNER 

FREEDOM— DROP LOCKS DEEP— ELGIN 

TYPE— BANKED TO DROP 



330. Corner Test. — Condition of Escapement — Drop locks 
deep. Excessive freedom between the slot corners and the roller 
Jewel. Banked to drop. 

Remarks — ^An observation of the drop locks of this escape- 
ment teaches us that the drop locks are rather deep. In addition, 
we learn from the corner test that a surplus of freedom or space 
exists under banked to drop conditions between the roller jewel 
and the slot corners. 

Alterations — The Locks — Following the rule the locks are 
first altered into a more correct form. To do so the pallet stones 
were pushed further back into their respective settings. 

The Bankings — Decreasing the drop locks enabled us to 
bring the bankings closer together, thereby a new drop lock 
position is obtained. 

The Lever — The results obtained by lessening the locks and 
the establishment of a closer banked to drop position of the 
bankings is, the slot corners are brought nearer to the path of 
the roller jewel and in consequence the excessive corner freedoms 
are lessened. 

Remarks — ^When a deep drop lock is associated with an excess 
of corner freedom, as a general rule, changing the deep to a 
lighter and more correct form of lock, automatically acts as a 
corrective of surplus corner freedoms. 



104 



LESSON 40 



TEST LESSON NO. 4 A— CORNER FREEDOM 

LACKINO-DROP LOCKS CORRECT— ELGIN 

TYPE— BANKED TO DROP 



331. Corner Test. — Condition oj Escapement — Drop locks 
correct. Corners of the slot and roller jewel either too close or 
in actual contact. Banked to drop. 

Remarks — The drop locks of this escapement are of a correct 
type. The corner test (escapement banked to drop) shows either 
contact or a decrease of the usual amount of corner freedom. 
The locks being correct, the position of the banking pins will 
therefore remain unchanged. 

The Lever — As no alterations of the locks are necessary or 
allowable, we must, to correct the want of corner freedoms, 
either shorten the lever's acting length or in some manner 
decrease the radius of the roller jewel. 

Remarks — As a precaution against the introduction of other 
errors, freely use the corner, corner safety and angular tests. 
As before mentioned, the corner test shows an absence or lack 
of the usual amount of corner freedom. As the drop locks are 
correct the angular test shows that each tooth is discharged from 
its respective pallet jewel. When we find the drop locks correct 
and corner freedom lacking we can assign the cause to either 
of the following: (a) the lever's acting length is too long or (b) 
the radius of the roller jewel is too great. Shortening the roller 
jewel radius is the plan usually followed in the factories. (See 
Lesson 36.) 



105 



LESSON 41 



TEST LESSON NO. 4 B— CORNER FREEDOM 

LACKING— DROP LOCKS LIGHT— ELGIN 

TYPE— BANKED TO DROP 



332. Corner Test. — Condition of Escapement — Drop locks 
ligTit. The corners of the slot and the roller jewel are either 
very close or come in contact. Banked to drop. 

Remarks — By observation we determine that the drop locks 
are light and unsafe. The corner test discloses a shortage of 
freedom — that is, the roller jewel is in close proximity to the 
slot corners. 

Alterations — The Locks — ^As there is an error in the drop 
locks, we give it first attention. Accordingly we increase the 
drop locks. 

The Bankings — Increasing the drop locks compel us to spread 
the bankings apart. 

The Lever — The effect of opening the bankings to a new 
position of drop lock, provides more freedom between the roller 
jewel and slot corners. To confirm the changes use the corner 
and angular tests. 



106 



LESSON 42 



TEST LESSON NO. 4 C— CORNER FREEDOM 

LACKING— DROP LOCKS DEEP— ELGIN 

TYPE— BANKED TO DROP 



333. Corner Test. — Condition of Escapement — Drop locks 
deep. Slot corner and roller jewel in contact or nearly so. 
Banked to drop. 

Remarks — ^As above stated, the drop locks are too deep. The 
corner test, the watch being banked to drop, brings out the fact 
that but little if any freedom can be found between the slot 
corners and the roller jewel. 

Alteration — The Locks — Our first alteration is the locks; 
these we decrease and make correct. 

The Bankings — To maintain banked to drop positions we 
must, when the drop locks are lessened, turn in each banking 
pin. 

The Lever — In this escapement, lessening the locks and re- 
banking to drop makes matters worse, the corner freedom being 
still further decreased. To remedy the want of corner freedom, 
we must either shorten the lever by cutting away the horns and 
slot corners, or else try shifting the roller jewel closer to the 
center of its table. Check the changes by the corner and angu- 
lar test. When conditions equivalent to "proof-findings" of the 
angular test are obtained we realize that the length of the lever 
is adapted to the extent of the drop lock. 



107 



LESSON 43 



TEST LESSON NO. 5 A — ROLLER JEWEL 

RETAINED IN SLOT— DROP LOCKS CORRECT 

—BANKED TO DROP— ELGIN TYPE 



334. Condition of Escapement. — Drop locks correct. Roller 
jewel unable to leave slot. Banked to drop. 

Remarks — Observation shows the drop locks are correct. 
With the escapement danked to drop the roller jewel we find is 
unable to make its exit out of the slot. Given the above condi- 
tions, we reason as follows: 

The drop locks are correct, therefore the present banked to 
drop position of the banking pins cannot be changed. The roller 
jewel, however, is unable to escape out of the slot. 

Alterations — Under the existing escapement conditions — 
namely, locks correct and the roller jewel held by the slot — we 
are led to decide that either the lever's acting length is too long 
or the roller jewel is set too far forward, or combinedly they 
cause the error. It therefore can be reasoned out that if we cut 
away a part of the horns and slot corners the roller jewel will 
be able to emerge out of the slot. Don't neglect constant use of 
the corner and angular tests to decide when normal conditions 
have been met. 



108 



LESSON 44 



TEST LESSON NO. 5 B — ROLLER JEWEL 
RETAINED IN SLOT— DROP LOCKS LIGHT- 
BANKED TO DROP— ELGIN TYPE 



335. Condition of Escapement — Drop locks light. Roller 
jewel unable to leave slot. Banked to drop. 

Remarks — The drop locks we learn are unsafely light. 
When the escapement is banked to drop the roller jewel is held in 
the slot and unable to make its slot. 

Alterations — Alterations are commenced by making the locks 
deeper. Increasing the locks compels us to rebank to drop. In 
this instance rebanking means, first, the spreading of the bank- 
ings apart; second, an increase of the corner freedom. These 
alterations may provide the correct amount of corner freedom. 
In the event of the corner freedom still being deficient, either 
the lever's length will have to be shortened, or the roller jewel 
set nearer the center of the table. The corner and angular test 
will decide when the escapement is in good condition. 



LESSON 45 



TEST LESSON NO. 5 C — ROLLER JEWEL 
RETAINED IN SLOT— DROP LOCKS DEEP- 
BANKED TO DROP— ELGIN TYPE 



336. Condition of Escapement. — Drop locks deep. Roller 
jewel unahle to make exit out of slot. Banked to drop. 

Remarks — By observation we decide that the drop locks are 
deep. When the escapement is banked to drop we find that the 
roller jewel is unable to get out of the slot. 

Alterations — The drop locks require first attention; on mak- 
ing the locks lighter we are thereby compelled to rebank to drop. 
Rebanking in this instance brings the banking pins closer to- 
gether, and it further decreased the chance of the roller jewel to 
emerge out of the slot. Therefore to obtain the release of the 
roller jewel, so that it can take its part in the escapement action, 
the lever's length must be made shorter, or the radius of the roller 
jewel decreased as formerly described. The corner and angular 
tests should be used to confirm changes. 



109 



LESSON 46 



TEST LESSON NO. 6 A — CORNER TRIPPING 
ERROR— ELGIN TYPE 



337. Corner Safety Test, — Condition of Escapement — ^Banked 
to drop. Drop locks correct. Corner test shows corner freedoms 
correct. Corner safety test develops a tripping error. 

Remarks — The Locks — ^The drop locks in this escapement are 
correct. 

Corner Test — ^The freedom of the roller jewel with the slot 
corners (corner freedom) is satisfactory. 

Corner Safety Test — By means of the corner safety test we 
find that the length of the escape wheel teeth vary, because some 
of the teeth show a safety lock, while others leave the pallet 
jewel's locking face. This latter condition being a corner trip, is 
of course an error. 

Alterations — The remedy, if the watch is worthy of It, is a 
new escape wheel, one possessing teeth regular in length. If the 
watch is a poor one, or should the charges not warrant a new 
wheel, the tripping can he overcome by increasing the locks. As 
a check on the result of alterations use the corner, corner safety, 
and angular tests. 



LESSON 47 



TEST LESSON NO. 6 B — CORNER TRIPPING 
ERROR— ELGIN TYPE 



338. Corner Safety Test. — Condition of Escapement — Banked 
to drop. Drop locks correct. Corner freedoms excessive.. A 
corner trip present. 

Remarks — The locks, as an inspection shows, are practically 
correct. The corner test reveals that too much freedom exists 



no 

between the slot corners and the roller jewel. When the corner 
safety test Is applied a corner trip is discovered. 

Alterations — If the corner freedom is only a trifle excessive 
and the resultant corner trip is also very slight, the corner trip 
can be corrected by either of the following methods: (a) slightly 
increasing the locks; (b) slightly advancing the position of the 
roller jewel. 

If the corner trip is of a most decided character, the drop 
locks being correct, we would then be compelled to either increase 
the lever's acting length, or bring the roller jewel more forward. 
By using one, or both methods combined, the corner trip can be 
eliminated. The corner, corner safety, and angular tests should 
be constantly employed to check whatever changes are made. 



LESSON 48 



TEST LESSON NO. 6 C — CORNER TRIPPING 
ERROR— ELGIN TYPE 



339. Corner Safety Test. — Condition of Escapement — Banked 
to drop. Drop locks light. Corner freedoms correct. Corner 
trip present. 

Remarks — When we discover a corner trip, the drop locks 
being light, but with the correct amount of corner freedoms 
present, we must, to correct the tripping error, increase the drop 
locks. 

Alterations — Making the drop locks deeper causes us to open 
the bankings. The result of these changes is to slightly Increase 
the corner freedoms. 

If after increasing the locks and rebanking the escapement 
to drop we find that the new corner freedoms are not too exces- 
sive, the surplus in the freedoms may be ignored. Unless proven 
to be detrimental by the corner, corner safety, and angular tests, 
in which event it requires to be remedied as directed in preceding 
lessons. 



Ill 



LESSON 49 



TEST LESSON NO. 6 D ^ CORNER TRIPPING 
ERROR— ELGIN TYPE 



340. Corner Safety Test. — Condition of Escapement — Banked 
to drop. Drop locks deep. Corner freedoms excessive. Corner 
trip present. 

Remarks — A complication of errors exist in this escapement. 
First, the drop locks are deep; second, there is too much freedom 
of the roller jewel with each slot corner; third, a corner trip is 
present. 

Our first alteration is that of decreasing the drop locks, 
changing them into a more correct form. The effect of lessening 
the locks is as follows: (a) There is a slight decrease in the 
excessive corner freedoms; (b) the tripping error is increased 
rather than decreased. 

We have now made the locks correct, but further changes are 
necessary to decrease both the excessive corner freedoms and 
the tendency of the parts to produce a trip. The required altera- 
tions consist in making the lever's acting length longer or ad- 
vancing the position of the roller jewel, as previously described. 
To confirm correctness of changes, use the corner, corner safety, 
and angular tests. 



112 



Index to Test Lessons 7 A to 1 2 A 



341 A. Guard Test and Guard Safety Test. 

LIST 7 

7 A. Drop locks light. Guard freedoms apparently 

correct. 
7B. Drop locks deep. Guard freedoms apparently 
correct. 

LIST 8 

8 A. Drop locks correct. Guard freedoms excessive. 
8 B. Drop locks light. Guard freedoms excessive. 

8 C. Drop locks light. Guard freedoms excessive. 

LIST 9 

9 A. Drop locks correct. Guard freedoms lacking. 
9B. Drop locks light. Guard freedoms lacking. 

9 C. Drop locks light. Guard freedoms lacking. 

LIST 10 
10. Guard point butts table. 

LIST 11 
11 A. Drop locks correct. Guard freedoms correct. 
Guard trip error. 

11 B. Drop locks correct. Guard freedoms excessive. 

Guard trip error. 
11 C. Drop locks light. Guard freedoms correct. 

Guard trip error. 
11 D. Drop locks light. Guard freedoms excessive. 

Guard trip error. 

LIST 12 

12 A. Drop locks deep. Guard freedoms excessive. 

Guard trip error. 



113 



LESSON 50 



TEST LESSON NO. 7 A— FALSE GUARD 
FREEDOM 



341 B. Candition of Escapement. — Drop locks light. Guard 
freedoms apparently correct. Banked to drop. 

The Locks — ^We assume that in this escapement, the drop 
locks are unsafely light. 

The Guard Freedoms — The escapement being banked to drop, 
we find, by means of the guard test, that the freedoms between 
the guard point and edge of table are apparently correct. 

Alterations — ^As we judged the drop locks to be too light, we 
increase them. Making the drop locks deeper, compels us to 
open out each banking — that is, we rebank the escapement to 
drop. The effect of spreading the banking pins is to increase the 
guard freedoms. 

The effect of the alterations is to place the escapement in 
the following condition: 

Altered Condition — Drop locks correct. Guard freedoms 
excessive. Banked to drop. 

The locks are now correct; but the guard freedoms are 
greater than before alterations were made. To remedy the in- 
crease in the guard freedoms, the guard point should be advanced 
closer to the table, or else obtain a new table of slightly greater 
diameter. 

Remarks — Whenever the guard freedom is altered, as a check, 
compare it with the corner freedom. Theoretically these free- 
doms should be equal, and from a practical standpoint it is wise, 
although not always practicable or possible, to maintain them 
so. If any difference is favored the corner freedom should be a 
trifle the greatest. 

In double roller escapements, when changes affecting the 
guard point are made, the curve test should be consulted for 
reasons explained elsewhere. (Compared with Lesson 35.) 



114 



LESSON 51 



TEST LESSON NO. 7 B— FALSE GUARD 
FREEDOM 



342. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks deep. Guard freedoms 
apparently correct. Banked to drop. 

The Locks — We discover by observation that the drop locks 
are deep. 

The Guard Freedoms — With the escapement banked to drop, 
the freedoms between the guard point and table appear satis- 
factory. 

Alterations — The deep drop locks require first attention, 
accordingly we change them into a more correct form of lock. 
Lessening the drop locks necessitates the closing of the bankings. 

In this instance the effect of rebanking to drop is to lessen 
the freedom of the guard point with the table. 

Assuming that the changes made bring about contact, or 
near contact, of the guard point with the table, the escapement's 
condition will appear as follows: 

Altered Condition — Drop locks correct. Guard freedoms 
none. Banked to drop. 

To correct the lack of guard freedom, the guard point must 
be set further back — that is, removed from the table; or a new 
table lesser in diameter should be supplied. 

At times it is permissible to use the lathe for turning away 
the edge of the original table. In this manner the diameter of 
the table can be lessened. Care should be taken to highly 
repolish its edge. 

Remarks — If in an effort to provide the requisite guard free- 
doms, the escapement being banked to drop, we bend the guard 
point away from the edge of the table, and find when the guard 
test is tried, that the guard point is inclined to stick or Jam 
against the edge of the table, our best procedure then is to 
readvance the guard point to its former position; then, to pro- 
vide the necessary freedom, the old table must be lessened in 
diameter, or a new table used, whose diameter provides the 
correct amount of guard freedom. Butting errors if developed 
always require correction. (Compare with Lesson 36.) 



H5 

LESSON 52 



TEST LESSON NO. 8 A— EXCESSIVE GUARD 
FREEDOM 



343. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks correct. Guard free- 
doms excessive. Banked to drop. 

The Locks — As above stated, the drop locks in this escape- 
ment are correct. 

Guard Test — The guard test shows there is too much freedom 
between the guard point and table. 

Alterations— As the drop locks are classed as correct, we 
pass on to the error of excessive guard freedom. To correct this 
error, we must either advance the guard point towards the table, 
or supply a new table of greater diameter. Whichever course we 
follow will remedy the error. 

As previously directed, compare the corner and guard free- 
doms — make use of the guard safety test, and in addition, If the 
escapement is of the double roller type, the curve test should be 
employed. 



LESSON 53 



TEST LESSON NO. 8 B—EXCESSIVE GUARD 
FREEDOM 



344. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks light. Guard free- 
dom excessive. Banked to drop. 

The Locks — The first fault we encounter is that of light drop 
locks. 

The Guard Freedoms. — The second fault, as uncovered by 
the guard test, is, there exists too much play or freedom between 
the guard point and edge of table. 

Alterations — The first items calling for correction are the 
drop locks. These we increase, making them deeper. Increasing 
the locks requires us to spread the banking pins more apart, and 
by doing so a new banked to drop position is established. 

The act of spreading the bankings increases the freedom 
between the guard point and table. This means we have iU' 
creased the error of excessive guard freedom. 

To correct excessive guard freedom the guard point must 
be brought closer to the edge of the table, or by supplying a new 
table greater in diameter; this will also provide the correct 
amount of guard freedom. (Compare with Lesson 38.) 



116 



LESSON 54 



TEST LESSON NO. 8 C— EXCESSIVE GUARD 
FREEDOM 



345. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks deep. Guard freedom 
excessive. Banked to drop. 

The Locks — By observation, and by banking the escapement 
to drop, we decide that the drop locks are too deep. 

The Guard Freedom — The guard test informs us that there is 
too much freedom between the guard point and the table. 

Alterations — Directing our attention to the deep locks, we 
reduce them to the standard of correct lock. Changing the locks 
allows us to close in each banking in accordance with banked 
to drop rules. By closing in the banking the excessive guard 
freedom is lessened, and whether now correct or not depends 
on actual conditions. (Compare with Lesson 39.) 



117 



LESSON 55 



TEST LESSON NO. 9 A—GUARD FREEDOM 
WANTING 



346. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks correct. Guard free- 
dom none or very little. Banked to drop. 

The Locks — In this escapement the drop locks are correct. 
We use the term "correct" to express the idea that the locks are 
"commercially right" and therefore satisfactory. 

The Guard Freedoms — The guard point possesses little if any 
freedom with the edge of the table. 

Alterations — The drop locks being classed as correct, require 
no changing. 

When the guard test was applied we therefrom learned that 
the customary amount of guard freedom was lacking. 

To overcome this state of contact, or of near contract, we 
must either remove the guard point from the table, or supply a 
new taJ)le of lesser diameter. 

The guard safety test, and the Rules preceding the Test 
Lessons, should be consulted, if difficulty is experienced about 
obtaining a correct adjustment of the guard point to the table. 
(Compare with Lesson 40.) 



118 



LESSON 56 



TEST LESSON NO. 9 B— GUARD FREEDOM 
WANTING 



347. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks light. Guard freedom 
none or very slight. Banked to drop. 

The Locks — We discover the drop locks are light. 

The Guard Freedoms — The guard test shows that guard 
freedom is lacking. 

Alterations — Our first move is to alter the locks, making 
same deeper, and at the same time correct. Increasing the drop 
locks compel us to spread the bankings to a new drop lock posi- 
tion. This change in the location of the banking pins, incidentally 
provides freedom between the guard point and the table. When 
the guard freedom approaches the extent of the corner freedom, 
it will be in agreement with correct escapement conditions. 
Should a butting error develop, Lesson No. 58 will be found 
helpful. (Compare with Lesson 41.) 



LESSON 57 



TEST LESSON NO. 9 C— GUARD FREEDOM 
WANTING 



348. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks deep. Guard freedom 
little, if any. Banked to drop. 

The Locks — An inspection of the drop locks, under banked 
to drop conditions shows they are deep. 

Guard Freedoms — By the guard test we learn that but little 
if any freedom exists between the guard point and the table. 

Alterations — We first change the deep to a correct drop lock. 
Decreasing the locks call for a rebanking to drop, the effect of 
which is to bring the banking pins closer together. The result 
of turning in the bankings is to make matters worse, the guard 
freedom being further lessened. 

To correct the want of guard freedom we must either remove 
the guard point away from the table or replace the old table with 
one lesser in diameter. Another remedy is, place the old table 
in the lathe and reduce its circumference. (Compare with Lesson 
42.) 



119 



LESSON 58 



TEST LESSON No. lo— BUTTING ERROR- 
ELGIN TYPE 



349. Guard Point Jams or Butts Against Edge of Table. — 
When, on making the guard or similar test, a workman finds 
that the guard point remains, or is inclined to remain in contact 
with the edge of the table, it is an indication of a butting error. 

Butting errors may be divided into three classes, as follows: 
First, errors due to defective draw; second, errors caused by the 
pivots of pallet or balance staff working in holes too large for 
them; third, a butting error arising from a guard point de- 
fectively placed, or caused by some fault in the size of the table. 

Butting errors are readily discovered without the escapement 
being banked to drop. Once this error is found it is of the utmost 
Importance that the escapement be banked to drop; by doing so 
the exact cause of the trouble can be located and corrections made. 
Butting errors must never be allowed to go uncorrected, or stop- 
page will ensue. 

Example 1 — ^We shall assume an instance wherein after bank- 
ing to drop, that too much guard freedom is found combined with 
a butting error. There is a likelihood that by advancing the 
guard point closer to the table, that the butting trouble can be 
overcome. 

It must be understood that a limit exists to the extent we 
can infringe on the guard freedom. While bringing the guard 
point closer to the table lessens the error, it may also injuriously 
affect the escapement, owing to the normal amount of guard 
freedom being decreased. 

Example 2 — ^When a butting error can only be overcome by 
placing the guard point unduly close to the edge of the table, we 
must, to obtain the correct amount of guard freedom, either lessen 
the size of the table, or provide a new table of lesser diameter. 
The plans suggested will supply the necessary amount of guard 
freedom, and abolish the butting tendency. 

Example 8 — Some escapements whose drop locks are correct, 
aud having an apparently correct amount of guard freedom, show 
an inclination of the guard point to butt against the edge of the 
table. To correct the difficulty the table's diameter must be made 



120 

less, and the guard point advanced toward the table's edge. Both 
alterations are necessary to correct the butting, and secure the 
requisite guard freedoms. 

In many escapements, butting errors are easily created, 
simply by bending the guard point a slight amount away from 
edge of table. Students are therefore advised to thus start a 
practical investigation of such errors. 

We wish to call attention to a type of butting error frequently 
met with — namely, (a) in setting a watch the seconds hand Is 
sometimes pushed backwards, the result often being that the 
watch stops; or, (b) when placing the seconds hand on post of 
fourth wheel stoppage follows. When such happens it is usually 
attributable to the guard point for some reason *'butting" or 
wedging against edge of table. The exact cause of error should 
be located and correction made. 



121 



LESSON 59 



TEST LESSON NO. ii A— GUARD TRIPPING 
ERROR 



350. Guard S<ifety Test.— Elgin type. 

Condition of Escapement. — Drop locks correct. Guard test 
shows correct guard freedom. Guard safety test develops a trip. 

The Locks — The drop locks in this escapement are correct. 

The Guard Test — ^We learn from the guard test that a correct 
amount of guard freedom is present. 

The Guard Safety Test. — The guard safety test shows a trip- 
ping error, involving only some teeth of the escape wheel. 

Alterations — ^As a guard tripping error is present and as some 
of the teeth show a trip while others show a safety lock, it Is 
clear that the cause is due to the teeth of the escape wheel being 
irregular in length. To remedy the trouble, supply a new escape 
wheel having teeth regular in length. Should the price obtain 
for repairing not be sufficient to cover the expense of a new wheel, 
we can continue the use of the old wheel by increasing the drop 
locks just enough to prevent tripping. 

Remarks — It is always advisable to examine the guard point; 
if loose, make it tight, and thereby avoid possible escapement 
troubles. 

The following advice will also be found profitable: When- 
ever, as a matter of testing, we bring the guard point in con- 
tact with one side of the table and a tripping error is found, 
and further tests on this particular side of the table agree in 
exposing more trips; while like tests on the opposite side of the 
table, all show safety locks, it would lead us to suspect that for 
some reason the edge of the table is running out of truth, or 
the guard point is bent to one side, or if straight, it is defective 
in shape. Of course faulty parts must be changed and retests 
made. (Compare with Lesson 46.) 



122 



LESSON 60 



TEST LESSON NO. ii B— GUARD TRIPPING 
ERROR 



351. Guard Safety Test. — Elgin Type. 

Conditions of Escapement — Drop locks correct. Guard free- 
dom excessive. Guard safety test exposes a trip. 

The Locks — As stated above, the drop locks are correct. 

Guard Test — The guard test shows that the freedom between 
guard point and table is excessive. 

The Guard Safety Test — The guard safety test shows that 
the teeth of the escape wheel do not remain on the pallet stone's 
locking face, but enter slightly on to the pallet's impulse face, 
thereby denoting that a tripping error is present. 

Alterations — The excessive guard freedom is the cause of 
the trip. If the extra amount of guard freedom is attributable 
to a guard point being inclined away from the table, then to 
correct the tripping error, and overcome the excessive guard 
freedom, the guard point must be straightened. 

If we find that the guard point is straight, the locks being 
correct, with a trip present, the instructions given in Test Les- 
sen No. 11 A will apply. (Compare with Lesson 47.) 



LESSON 61 



TEST LESSON NO. ii C— GUARD TRIPPING 
ERROR 



352. Guard Safety Test. — Elgin Type. 

Condition of Escapement — Drop lock light. Guard freedoms 
correct. Guard tripping error present. Banked to drop. 

Remarks — If a guard tripping error is discovered, when the 



123 

drop locks are light, and the freedom between the guard point 
and table is satisfactory, we can, by increasing the locks, over- 
come the tripping error. 

Alterations — The locks being light, we increase them. The 
effect of making the drop locks deeper brings about two results — 
first, the tripping fault is overcome; second, rebanking to drop 
compels us to spread the banking pins more apart. The effect 
of spreading the bankings is to increase the former correct 
freedoms into excessive freedoms. The usual experience is, that 
a slight increase in the guard and corner freedoms incident to 
a slight increase of the drop locks is not detrimental. Should 
the freedoms be injuriously excessive, consult Test Lessons 3 A 
and 8 A. (Compare with Lesson 48.) 



LESSON 62 



TEST LESSON NO. ii D— GUARD TRIPPING 
ERROR 



353. Guard Safety Test. — Elgin type. 

Condition of Escapement — Drop locks light. Guard freedoms 
excessive. Guard tripping error present. Banked to drop. 

Remarks — ^When we discover a guard trip, combined with 
too much freedom between guard point and table, the drop locks 
being too light, the following changes are necessary: 

Alterations — We first increase the drop locks; this, when we 
rebank to drop, causes us to spread the bankings. The escape- 
ment will then be in the following condition: 

Altered Condition — Drop locks correct. Guard freedom ex- 
cessive. Banked to drop. 

To correct the excessive guard freedom consult Test Lessons 
Nos. 8 A-8 B. Should the corner freedoms be likewise excessive 
see Test Lessons No. 38. 



124 



LESSON 63 



TEST LESSON NO. 12 A— GUARD TRIPPING 
ERROR 



354. Guard Safety Test. — Elgin type. 

Condition of Escapement — Drop locks deep. Guard freedoms 
excessive. Guard tripping error present. Banked to drop. 

Remarks — It is possible, even with deep drop locks, to dis- 
cover guard tripping errors, when there exists too much freedom 
between the guard point and the table. 

Alterations — The first change required is that of altering 
the deep into a correct form of lock. This done, the condition of 
the escapement will be: 

Altered Condition — Drop locks correct. Guard freedoms 
still excessive. Guard tripping error present. Banked to drop. 

Remarks — It is very likely that errors of excessive guard 
freedom, and guard trips, will be found associated with errors of 
excessive corner freedom and corner trips. The corrections indi- 
cated are outlined in Test Lessons Nos. 8 A, 3 A and 6 B. (Com- 
pare Lesson 49.) 



125 



Index to Test Lessons 1 3 A to 1 8 A 



355. Angular Test. — 

LIST 13 

13 A. Various findings with corrections indicated. 

14 A. Proof findings. 

15 A. Locks light. Lever length correct. 

16 A. Locks deep. Lever length correct. 

17 A. Locks correct. Lever length long. 

18 A. Locks correct. Lever length short. 



126 



LESSON 64 



TEST LESSON NO. 13 A— ELGIN TYPE 

STATEMENT OF FINDINGS BY THE ANGULAR 

TEST WITH INDICATED CORRECTIONS 



Remarks — Before using the angular test correct any defects 
found in the drop locks. Follow the instructions about first 
correcting the locks and you will be able with the assistance of 
statements Nos. 1, 2 and 3 to determine the nature of the fault. 
When the locks are corrected, faults if found, are then attribut- 
able to some defect in either the lever's acting length, or the 
radius of the roller jewel, or both. 

When the locks are not corrected beginners are apt to become 
confused over the test findings. Students should also study 
Statements 4, 5 and 6. The latter — viz.. Statement No. 6 — is a 
very exacting method for determining whether an escapement is 
out of angle. 

WHEN THE LOCKS ARE CORRECT 

356. Angular Test — Elgin type. 

Statement No. 1 — Drop locks correct. Lever's acting length 
correct (matches the lock). Result as shown by test. Tooth and 
pallet show contact (proof-findings) as indicated by Fig. 29. 

Statement No. 2 — Drop locks correct. Lever's length long (or 
roller jewel's radius long). Result shown by test. Each tooth 
discharged from pallet. (See Fig. 30.) 

Remedies — To establish proof-findings, shorten the lever's 
length, or radius of roller jewel, or both. 

Statement No. 3 — Drop locks correct. Lever's length short 
(or roller jewel's radius short). Result shown by test. Each 
tooth shows too much contact with its pallet jev/el. (See Fig. 
3L) 

Remedies — To establish proof-findings, increase lever's length, 
or roller jewel radius, or both. 

WHEN THE LOCKS ARE INCORRECT 

Angular Test — Elgin type. 

Statement No. 4 — Drop locks light. Lever's length correct. 



127 



Result shown by test. 
Fig. 30.) 



Each tooth discharged from pallet. (See 




Fig. 30 

Remedy — To establish proof-findings increase the drop locks. 
Btatement No. 5 — Drop locks deep. Lever's length correct. 






75^ 




Fig. 31 

Result shown by test. Each tooth has too much contact with its 
pallet. (See Fig. 31.) 

Remedy — To establish proof-findings lessen the drop locks. 

OUT OF ANGLE FINDINGS 
Statement No. 6 — Drop locks unequal. Results obtained by 



On one pallet, tooth shows too much contact (see Fig. 
tooth is discharged from the opposite pallet (see Fig. 



test: (1) 
31); (2) 
30). 

Or, 

The teeth occupy dissimilar positions on their respective 
pallet jewels. For instance, one tooth might remain in contact 
near the letting off corner of one pallet, while the other tooth on 
opposite pallet might be found near the pallet's entering corner. 

Remedy — Equalize the drop lock, then retest. 



128 



LESSON 65 



TEST LESSON NO, 14 A— PROOF FINDINGS- 
ELGIN TYPE 



357. Angular Test. — When by the angular test we discover 
that each tooth remains in contact with its pallet jewel, at a point 
very close to the releasing corner of the jewel (see Fig. 29), v/e 
feel sure the parts are well matched. 

If in addition to the proof findings, as expressed by the 
slight contact of each tooth with its pallet stone, we find that 
the drop lock is as light as is consistent with the construction of 
the escapement — that is, the drop lock belongs in either the 
correct or commercially correct class — we then know that the 
parts associated with the angular test are reasonably perfect and 
that their action will be satisfactory. 



LESSON 66 



TEvST LESSON NO. 15 A— ERROR, DROP LOCKS 

LIGHT 



358. Angular Test. — Elgin type. 

Condition of Escapement — Drop locks light. Lever's length 
correct. 

When the drop locks are light and the lever's acting length 
is correct, the angular test will exhibit the error by discharging 
each tooth from each pallet. (See Fig. 30.) 

If we increase the drop locks, making them normal, we will 
find, on repeating the angular test, that each tooth remains in 
slight contact with its pallet. (See Fig. 29.) The contact taking 
place near the letting-off corners of each pallet stone, in con- 
formity with the proof findings. 



129 



LESSON 67 



TEST LESSON NO. i6 A— ERROR, DEEP 
DROP LOCKS 



359. Angular Test. — Elgin type. 

Condition of Escapement — Drop locks deep. Lever's length 
correct. 

Given the drop locks as deep, and the lever's acting length 
as correct, the angular test will show a surplus of contact of the 
teeth with their respective pallet jewels. (See Fig. 31.) The 
position occupied by the teeth on each pallet stone's impulse 
face, depends altogether upon how deep is the drop lock. 

By reducing the deep locks into a more correct form we can 
secure the proof findings of the angular test. (See Statement 
No. 5, Test Lesson No. 13 A.) 



130 



LESSON 68 



TEST LESSON NO. 17 A— ERROR, ACTING 
LENGTH OF LEVER LONG 



360. Angular Test. — Elgin type. 

Condition of Escapement — Drop locks correct. Lever'3 
length long. 

If the drop locks are correct and the lever's acting length is 
long, the angular test will show the teeth as discharged from 
their respective pallet jewel's. (See Fig. 30.) 

The remedy is to shorten the lever. During the progress 
of alterations, make frequent use of the angular test, thereby 
avoid cutting the lever too short. (See Statement No. 2, Test 
Lesson No. 13 A.) 



LESSON 69 



TEST LESSON NO. 18 A— ERROR, ACTING 
LENGTH OF LEVER SHORT 



361. Angular Test. — Elgin type. 

Condition of Escapement — Drop locks correct. Lever's length 
short. 

When the drop locks are correct and the lever's acting length 
is short, the angular test will show over contact of the teeth with 
their respective pallet jewels (see Fig. 31) — that is, contact takes 
place at a point some distance from the letting off corner of each 
pallet stone. 

The remedy required is a new lever of greater acting length, 
or try advancing the roller jewel more forward; consult the 
following: Statement No. 3, Test Lesson No. 13 A; also Test 
Lesson No. 3 A. 



131 

Index to Test Lessons 1 9 A to 21 C 



Out of Angle 

S62. Out of Angle. — 

LIST 19 
19 A. Out of Angle Test Findings. 
19 B. Drop Locks Unequal. Lever Straight. 

19 C. Drop Locks Unequal. Lever Bent. 

LIST 20 

20 A. Drop Locks Unequal. Lever Straight. Guard 

Freedoms Unequal. 

20 B. Drop Locks Unequal. Lever Bent. Guard Free- 

doms Unequal. 

LIST 21 

21 A. Drop Locks Unequal. Lever Straight. Corner 

Freedoms Unequal. 
21 B. Drop Locks Unequal. Lever Bent. Corner Free- 
doms Unequal. 



132 

LESSON 70 



TEST LESSON NO. 19 A— ELGIN TYPE 



363. Out 0/ Angle. — An escapement is out of angle: 

(a) When the drop locks are unequal. 

(b) When the guard freedoms are unequal. 

(c) When the corner freedoms are unequal. 

(d) When the angular test shows dissimilar positions of each 
tooth with its respective pallet jewel. 



LESSON 71 



TEST LESSON NO. 19 B— ERROR, OUT OF 
ANGLE 



a64. Angular Test. — Elgin type. 

Condition of Escapement — Drop locks unequal. Lever 
straight. 

When the drop locks are found to be unequal — viz., the drop 
lock on one pallet stone exceeds the drop lock on the opposite 
stone — we immediately know that the escapement is out of 
angle. As the lever quoted above is straight, the defect is wholly 
attributable to the faulty locks. 

By using the angular test to expose the out of angle condition 
of the escapement, we will find that the teeth occupy dissimilar 
positions on their respective pallet jewels. 

As the lever is straight, the correction required is that of 
equalizing the drop locks. This alteration will place the escape- 
ment in angle, and cause it to conform with the proof findings 
expressed in Test Lesson No. 14 A. 



133 

LESSON 72 



TEST LESSON NO. 19 C— ERROR, OUT OF 
ANGLE 



365. Angular Test — Elgin Type. 

Condition of Escapement — Drop locks unequal. Lever hent. 

In this escapement not only are the drop locks unequal, but 
the lever is bent. 

The first altertation is that of straightening the lever. This 
may have the effect of equalizing the drop locks. Should straight- 
ening the lever fail to equalize the locks, we must, in order to 
place the escapement in angle, reset the pallet jewels. The pallet 
^ones should be reset to meet the requirements of correct lock. 



LESSON 73 



TEST LESSON NO. 20 A— ERROR, OUT OF 
ANGLE 



366. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks unequal. Lever 
straight. Guard point straight. Guard freedoms unequal. 
Banked to drop. 

When the lever and guard point are straight, and the drop 
locks and guard freedoms are unequal we realize that the escape- 
ment is out of angle. 

Given an escapement in the above condition, we can, by 
making the drop locks equal, correct the unequal guard freedoms ; 
this change places the escapement in angle. 

As an additional confirmative that the escapement is in angle 
make use of the angular test. 



134 

LESSON 74 



TEST LESSON NO. 20 B— ERROR, OUT OF 
ANGLE 



367. Guard Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks unequal. Lever bent. 
Guard point straight. Guard freedoms unequal. Banked to 
drop. 

The drop locks in this escapement are unequal, and the lever 
is bent. The guard test, with the escapement banked 10 arop 
shows a greater amount of freedom on one side than on opposite 
side of table. Both appearance and test show that the escapement 
is out of angle. 

In all cases, where we find that the lever is bent, the first 
alteration is that of straightening the lever; this change is always 
followed by a rebanking of the escapement to drop, and a rein- 
spection of the drop locks. If after straightening the lever the 
drop locks still remain unequal or otherwise imperfect the pallet 
stones must be reset in conformity with the requirements of 
correct lock — viz., a drop lock suited to the particular escape- 
ment in hand. When satisfactory alterations have been made 
the guard freedoms, like the drop locks, will be equalized. 

Whenever we find that a lever is bent only a fractional 
amount, and the resulting inequalities of the drop locks are very 
slight, corrections are seldom necessary. 

When the lever is bent to such an extent that the bend is 
plainly visible, it is advisable to straighten it, besides mating 
other corrections if required. 

At times we find an escapement with the lever bent, but 
having equal drop locks; when this occurs, conditions, and tests 
will decide what changes will improve the escapement. 

LESSON 75 



TEST LESSON NO. 21 A— ERROR, OUT OF 
ANGLE 



368. Corner Test. — Elgin type. Banked to drop. 



135 

Condition of Escapement — Drop locks unequal. Lever 
straigh.t Corner freedoms unequal. Roller jewel straight. 
Banked to drop. 

We have in this instance, to contend with unequal drop locks 
and unequal corner freedoms. This inequality of the freedoms 
means that the escapement is out of angle. As the lever is 
straight, the cause of the escapement being out of angle is due 
to the drop locks being unequal; by correcting the error in the 
drop locks the corner freedoms will be equalized. Altering the 
locks therefore places the escapement In angle; this can be con- 
firmed by the angular and guard test. 



LESSON 76 



TEST LESSON NO. 21 B— ERROR, OUT OF 
ANGLE 



369. Corner Test. — Elgin type. Banked to drop. 

Condition of Escapement — Drop locks unequal. Lever bent. 
Roller jewel straight. Corner freedoms unequal. Banked to 
drop. 

The conditions state three errors — viz., unequal drop locks, 
unequal corner freedoms, and the lever is bent. These faults we 
must rectify to overcome the error of out of angle. 

The first alterations are, straightening the lever, and re- 
banking to drop. Should the locks remain unequal after making 
the lever straight it would be necessary to make the drop locks 
equal and otherwise correct. 

Assuming we have made the corrections, we will find by the 
corner test that the corner freedoms are equal. The guard test 
will show the guard freedoms are also equal, and the angular 
test will further confirm the verity of our work. 



136 

Index to Test Lessons 22 A to 26 A 



CURVE TEST AND CURVE SAFETY TESTS 
370. Curve Test and Curve Safety Tests. — 

LIST 22 
22 A. End of Horn. Double Roller. Curve Test. 
22 B. Central Part of Horn. Double Roller. Curve 
Test. 

22 C. Slot Corners. Double Roller. Curve Test. 

23 A. Curve Safety Test. Double Roller. 

24 A. End of Horn. Single Roller. Curve Test. 

25 A. Horn and Slot Corners. Single Roller. Curve 

Test. 

26 A. Curve Safety Test. Single Roller. 



137 

LESSON 77 



TEST LESSON NO. 22 A— END OF HORN- 
DOUBLE ROLLER 



371. Curve Test. — 

Note — The following lessons on the curve and curve safety 
tests, as applied to single and double roller escapements, are a 
repetition of former explanations. The facts which the lessons 
contain must be known to you. 

To learn if the roller jewel can touch the extreme end 0/ 
horn : 

Method — Revolve the balance so as to bring the roller jewel 
beyond the tip of the horn, then hold the balance secure, next 
with a fine broach or watch oiler lift the lever off its bank, 
thereby causing contact of the guard point with edge of safety 
table. Maintain the parts in contact while you slowly rotate the 
balance so as to bring the roller jewel back past the end of the 
horn, and towards the lever slot. If these parts are correctly 
related, the roller jewel as it passes will be free from the end of 
the horn. While a rub of the parts when passing is allowable, 
anything resembling a catch calls for some alteration either to 
tip of horn or roller jewel. Consult the curve safety test before 
making any change. 



LESSON 78 



TEST LESSON NO. 22 B— CENTRAL PART OF 
HORN—DOUBLE ROLLER 



372. Curve Test. — The object of this division of the curve 
test is to find out, if, in a double roller escapement, the central 
parts of the lever horn can catch or hold the roller jewel, and to 
learn the condition of the curve safety lock. 

Method — The lever is lifted off its bank at a time to cause 
contact, of the central parts of the lever horn with the roller 
jewel. Hold the parts in contact and slowly rotate the balance. 



138 

The rotation of the balance causes the roller jewel to rub along 
the face of the horn; this rub is to be expected, but nothing re- 
sembling a catch should be felt. If a catch is detected, do not 
confuse a catch caused by a tripping error with a catch due to a 
fault in the shape of the horn, or in the position of the roller 
jewel. Before altering the shape of the horn in a double roller 
escapement make a careful inspection of the safety locks. (See 
curve safety test.) 



LESSON 79 



TEST LESSON NO. 22 C— SLOT CORNERS- 
DOUBLE ROLLER 



373. Curve Test. — We employ this section of the curve test 
to learn if the roller jewel can catch on, or in the vicinity of the 
slot corners. 

Method — Bring the roller jewel, and that part of the lever 
horn very close to the slot corner into contact. Next rotate the 
balance so as to bring the roller jewel into the slot. During the 
rotation of the balance, contact of the horn with the roller jewel 
will be felt; also when the roller jewel passes the slot corner a 
rubbing of the parts will be felt. The rubbing is permissible, 
but a catch is not allowable. Should the roller jewel catch on the 
horn, or on the slot corner make use of all tests and correct all 
other errors before altering the relation of the curve of the horn 
to the roller jewel. Both horns of course should be tested. 



LESSON 80 



TEST LESSON NO. 23 A— DOUBLE ROLLER 



374. Curve Safety Test. — The purpose of the curve safety 
test is to determine if a safety lock of tooth on pallet is present, — 



139 

when any part of the curve of the horn is in contact with the 
roller jewel. 

In a double roller escapement the moment the guard point 
enters the crescent, the roller jewel and horn can be brought in 
contact, simply by lifting the lever off its bank. When these parts 
are in contact the safety lock should be sound. 

The safety lock in a double roller escapement should be 
inspected in the following positions: First, at the moment the 
guard point enters the crescent; secondly, from about the central 
part of the horn up to the slot corner; thirdly, when the roller 
jewel is opposite the slot corner. 

Defects in the safety locks, no matter from what cause, 
always demand correction. Before altering the shape of any 
part of the horn, use other escapement tests as a confirmative 
that the fault is really due to a defect in the shape of the horn. 



140 

LESSON 81 



TEST LESSON NO. 24 A— END OF HORN- 
SINGLE ROLLER 



375. Curve Test. — The intention of this part of the curve test 
Is to learn, if in a single roller escapement, the roller jewel can 
catch on the end, or central parts of the horn. 

Method — Bring the guard pin in contact with the edge of the 
table, hold the parts in contact while the balance is being rotated 
so as to bring the roller jewel past the end and central part of 
the horn. No contact of the roller jewel with this part of the 
horn should be felt; there is, however, no real objection to the 
parts rubbing so long as nothing resembling a catch is detected. 
If a catch develops alterations should be made. 

As a matter of fact, in single roller escapements that part of 
the horn from the tip to the central part could be dispensed with 
without jeopardizing the escapement.. The curve test in single 
roller escapements is of little importance and can usually be 
omitted. 



LESSON 82 



TEST LESSON NO. 25 A— HORN AND SLOT 
CORNERS— SINGLE ROLLER 



376. Curve Test. — The object of this division of the curve 
test is, to determine if the roller jewel under any circumstances 
can catch on the slot corners, or on that part of the horn near 
the slot corners (single roller escapement). 

Method — Rotate the balance so as to bring that part of the 
table's edge adjacent to the crescent, opposite the guard pin. 
When the parts are in the position mentioned, lift the lever oft 
its bank, thereby causing the guard pin to touch the edge of the 
table. If the directions have been carefully followed, the guard 



141 

pin will touch the edge of the table at a point very close to the 
crescent. Maintain pressure against the lever and rotate the 
balance just enough to bring the guard pin barely inside the 
crescent. The instant the guard pin enters the crescent, ana 
because of the pressure exercised on the lever, the horn and 
roller jewel come into contact with each other. If the curve or 
the horn is adapted to the position of the roller jewel the latter 
will rub over the face of the horn and past the slot corner in a 
smooth manner, or at least without developing any undue amount 
of friction. No catch of the parts is permissible; if such is 
discovered an alteration is required. Never jump at a conclusion, 
but make use of many tests to determine the cause of a fault. 



LESSON 83 



TEST LESSON NO. 26 A— SINGLE ROLLER 



377. Curve Safety Test. — The curve safety test as employed 
in single roller escapements is used to determine the existence of 
tripping errors. 

Method — To learn if a tripping error is present, bring the 
curve of the lever horn in contact with the roller jewel after the 
manner described in Test Lesson No. 25 A; then, while the partjs 
are held in touch with each other, examine the safety lock. 
Should a tripping error be located, employ other escapement 
tests before assigning the cause of the error to either a defect 
in the curve of the horn, or position of the roller jewel. 



142 

Index to Test Lessons 27 A to 29 B 



EXAMINATIONS AND TEST FINDINGS 

378. Escapement Examination — Elgin and Soutli Bend. — 

LIST 27 
27 A. Escapement Examination. Error, Deep Drop 

Locks. 
27 B. Escapement Examination. Error, Light Drop 

Locks. 

27 C. Escapement Examination. Error, Unequal Drop 

Locks. 

LIST 28 

28 A. Proof Findings, Elgin and Soutli Bend Con- 

trasted. 

LIST 29 

29 A. South Bend Escapement. Error, Light Locks. 
29 B. South Bend Escapement. Error, Deep Locks. 



143 

LESSON 84 



COMPARISONS OF THE TESTS 



TEST LESSON NO. 27 A— DEEP DROP LOCKS- 
ELGIN TYPE 



379. Examining an Escapement. — 

Remarks — The three following lessons are designed to make 
you familiar with the full routine of escapement testing. You 
will find it to your advantage to compare similar test find- 
ings in all three lessons. Of course, when a comparison is made 
bear in mind the difference in the locks. Although the routine is 
apparently extensive enough to consume a great deal of time, as 
a matter of fact, once you are acquainted with the tests, two to 
five minutes will decide if changes are necessary. That it is not 
always necessary to follow out the full routine of testing can be 
learned by studying "Bench Problems." One soon becomes 
familiar with cause and effect and can then quickly locate any 
defect liable to cause escapement trouble. In the previous "Test 
Lessons" each "test" is separately treated — here we have them 
comdined. 

It is assumed that the escapements we are about to examine 
were originally perfect, but some one changed their respective 
locks into deep, light and unequal. The length of the levers, the 
position of each roller jewel, the location of the guard points, and 
sizes of tables are exactly right. When the drop locks are matched 
to the respective length of the levers, each escapement will then 
belong to that class we have designated correct, or at least com- 
mercially correct. The student should closely study Lesson No. 
87, in which the escapement types and tests are contrasted. 

Condition of Escapement — Drop locks deep but equal. Corner 
freedoms excessive. Guard freedoms excessive. 

Angular Test Findings (Elgin) — The angular test shows that 
each tooth has too much contact with its pallet stone as illus- 
trated by Fig. 31. 

Corner Test Findings, Banked to Drop (Elgin) — By the 
corner test we discover an excess of freedom between the roller 
jewel and each slot corner. (Corner freedom.) 

Corner Safety Test Findings (Elgin) — When the slot corners 
are held in contact with the roller jewel there is an overabund- 
ance of safety lock. 

Guard Test Findings, Banked to Drop (Elgin) — By the guard 
test a surplus of freedom is found between the guard point ana 
edge of table. (Guard freedom.) 



144 

Butting Test Findings — There is no evidence of a tendency 
of the guard point to butt or stick against edge of table. 

Guard Safety Test Findings — ^An excessive amount of safety 
lock is noticeable. 

Curve Test Findings — This test shows that the relationship 
of the horns to the roller jewel is normal. 

Curve Safety Test Findings — Contact of the horn with the 
roller jewel shows as in the other safety tests, a great amount 
of safety lock. 

Draw — The condition of the draw is satisfactory. 

Drop, Inside and Outside — On account of the deep locks the 
extent of the drop is curtailed. 

Shake, Inside and Outside — As we discovered a lessened 
amount of drop, we correspondingly find the shakes dangerously 
decreased. (Students should learn to realize the importance of 
shake.) 

Tooth and Pallets' Impulse Planes — The action of each tooth 
over each pallet jewel's impulse face is fairly satisfactory. 



145 



LESSON 85 



COMPARISONS OF THE TESTS— TEST LESSON 
NO. 27 B-=-DROP LOCKS LIGHT--ELGIN TYPE 



380. Note. — The assumption is that this escapement was cor- 
rect when it left the factory, but afterwards some one made the 
drop locks lighter. 

Condition of Escapement — Drop locks light but equal. Corner 
freedoms deficient. Guard freedoms deficient. 

Angular Test Findings (Elgin) — The angular test shows each 
tooth as discharged from its pallet jewel. (See drawing No. 30.) 

Corner Test Findings, Banked to Drop (Elgin) — The corner 
test shows a want of the correct amount of freedom between the 
slot corners and roller jewel. (Corner Freedoms.) 

Corner Safety Test Findings — A deficiency of safety lock is 
observed, when the slot corners are held in contact with the 
roller jewel. 

Guard Test Findings, Banked to Drop (Elgin) — ^We discov- 
ered by the guard test that there is a want of freedom between 
the guard point and edge of table. (Guard freedom.) 

Butting Test Findings — No tendency of the guard point to 
butt or stick against the edge of the table is found. 

Guard Safety Test Findings — The extent of the safety locks 
are less than desirable. 

Curve Test Findings — The curve test does not show any 
irregularities of the horn with the roller jewel. 

Curve Safety Test Findings — When the horns and roller Jewel 
are in contact, we again find the safety locks are deficient. 

Draw — The condition of the draw is satisfactory. 

Drop, Inside and Outside — The amount of drop, both inside 
and outside, is somewhat excessive. 

Shake, Inside and Outside — The shakes, inside and outsiae, 
show plenty of freedom. 

Tooth and Pallet's Impulse Plane — The action of the escape 
wheel teeth over the impulse planes of the pallet jewels are 
satisfactory. 



146 



LESSON 86 



COMPARISON OF THE TESTS— TEST LESSON 



NO. 27 C— DROP LOCKS UNEQUAL— 
ELGIN TYPE 



381. Examining an Escapement. — 

Note — Originally this escapement was perfect, but somebody 
tampered with the drop locks, making them unequal ; consequently 
the escapement is out of angle. 

Condition of Escapement — Drop locks unequal. Corner free- 
dom, on one corner excessive. Corner freedom, on opposite cor- 
ner deficient. Guard freedom on one side excessive. Guard free- 
dom on opposite side deficient. 

Angular Test Findings (Elgin) — As the drop locks are un- 
equal, the angular test shows dissimilar positions of contact of 
each tooth with each pallet; or perhaps, one tooth shows too 
much contact, while the other tooth is discharged from the 
opposite pallet jewel. 

Corner Test Findings, Banked to Drop (Elgin) — The corner 
test shows an excessive amount of corner freedom on one corner, 
while on the opposite corner the amount of corner freedom is 
very deficient, or at least we find that the corner freedoms are 
unequal. 

Corner Safety Test Findings — On one corner we find a sur- 
plus of safety lock. The opposite corner shows a shortage of 
safety lock. 

Guard Test Findings, Banked to Drop (Elgin) — The guard 
test reveals too much freedom on one side of the table, and too 
little on the oposite side. 

Butting Test Findings — A butting error is not discoverable. 

Guard Safety Test Findings — ^We find on one pallet jewel an 
excessive amount of safety lock. On the opposite pallet the safety 
lock is deficient or wanting. 

Curve Test Findings — No defects of curve of horn with roller 
jewel are found by this test. 



147 

Curve Safety Findings — When the roller jewel is brought 
into contact with one curve of the horn a great amount of safety- 
lock is found. A similar test, with the opposite curve of horn, 
shows a shortage of the safety lock. 

Draw — The draw is fairly satisfactory. 

Drop, Inside and Outside — The drops are unequal — ^viz., the 
inside drop differs in extent from the outside drop. 

Shake, Inside and Outside — The shakes, like the drops, are 
also unequal. The lesser of the two shakes probably show a 
dangerous lack of freedom. 

Tooth and Pallets' Impulse Plane — The action of each tooth 
over the impulse faces of the pallet jewels will perhaps be fair. 



148 



LESSON 87 



ESCAPEMENT CORRECT— TESTS AND TYPES 



CONTRASTED— TEST LESSON NO. 28 A— 
PROOF FINDINGS 



382. Elgin and South Bend Proof Findings. — 

Angular Test, Proof Findings, Elgin Type — In tne Elgin 
type of escapement the angular tests proof findings show a slight 
contact of each tooth with each pallet. (See Fig. 29.) 

Angular Test, Proof Findings, South Bend Type — ^The South 
Bend escapement will show results contrary to above — namely, 
the escape wheel teeth are discharged from their respective pallet 
jewels. (See Fig. 30.) 

Corner Test, Proof Findings, Elgin Type, Banked to vrop — 
The proof findings of the corner test will show when the escape- 
ment is banked to drop, a certain amount of freedom between 
the roller jewel and slot corners. (Elgin type.) 

Corner Test, Proof Findings, South Bend Type, Banked to 
Drop — V^hen the escapement is banked to drop the proo* findings 
show contact of the roller jewel with the slot corners. (South 
Bend type.) 

Guard Test, Proof Findings, Elgin Type, Banked to Drop — 
The proof findings of an Elgin type of escapement when banked 
to drop shows freedom between the guard point and table. 

Guard Test, Proof Findings, South Bend Type, Banked to 
Drop — Contact of the roller jewel with the slot corners when the 
escapement is banked to drop is the correct proof findings ror 
Due'ber and South Bend escapements. 

In this "Lesson" toe have contrasted the correct or proof 
findings of each test for escapements of the Elgin and South Bena 
types. Their distinctive differences must be recognized. 



149 



LESSON 88 



TEST LESSON NO. 29 A— ERROR, LIGHT LOCK 



383. South Bend Escapement, Comparison of Tests. — 

Note — The escapement in this lesson is assumed to be of tne 
South Bend type. It possesses but one real error — namely, the 
drop locks are unsafely light. The effect of unsafe locks Is 
shown by the various tests. A comparison of the tests in this and 
the following lesson will be found profitable if we bear In mlnfl 
the opposite defects in the locks — viz., one is light, and the other 
deep. The contrasting differences should be remembered. 

Angular Test (South Bend) — The teeth of the escape wheel 
remain in contact with their respective pallet jewels. This is 
contrary to the proof findings for this type of escapement. 

Corner Test, Banked to Dr^op (South Bend) — The drop locks 
are light, and to meet the requirements of this test the escape- 
ment is banked to drop; combinedly these conditions prevent the 
roller jewel from either entering or leaving the slot, consequently 
the corner test cannot be made. 

Guard Test, Banked to Drop (South Bend) — To make the 
guard test, it is also necessary to bank the escapement to drop, as 
the drop locks are light, the banking pins stand closer together 
than they should. The result is the guard point is jammed against 
the edge of the table, which makes the test unsatisfactory. 



150 



LESSON 89 



TEST LESSON NO. 29 B— ERROR, DEEP LOCKS 



384. South Bend Escapement — Comparison of Tests. — 

Note — The error in this escapement is the drop locks are 
deep. We again assume that this is the only defect, the remain- 
isQg escapement parts being perfect. 

Angular Test (South Bend) — The error of deep locks is 
recognized by the fact that the escape wheel teeth show an over- 
contact — viz., too much contact of the teeth with their respective 
pallet jewels. (See Fig. 31.) 

Corner Test, Banked to Drop (South Bend) — The error as 
shown by the corner test is that freedom is found between the 
slot corners and roller jewel, freedom being an incorrect corner 
test finding for this type of escapement. 

Guard Test, Banked to Drop (South Bend) — The guard test, 
like the corner test, shows freedom between the guard point and 
table. The finding is incorrect for this type of escapement. 

The foregoing lessons on South Bend escapements should be 
studied in connection with our previous instructions. This will 
place students in command of the main features controlling 
escapements of this type. 



151 



BENCH PROBLEMS 



Index to Bench Problems Nos. 1 to 1 4 



385. 1. Locks deep. Lever Long. 

2. Locks light. 

3. Butting error. 

4. Lever long. Table small. 

5. Defective entry of tooth onto pallet's impulse face. 

6. Want of inside shake. 

7. Deep locks. Guard pin radius long. Lever long. 

8. Out of angle. Lever bent. 

9. Out of angle. Locks irregular. 

10. Out of angle. Locks deep and irregular. Lever 

bent. 

11. Locks deep and irregular. Draw bad. 

12. Deep locks. Curve of horns. 

13. Light locks and a corner trip. 

14. Deep locks. Long lever. Table large. 



152 



LESSON 90 



The following lessons under the title of bench problems have 
been taken from actual experiences at the bench. As the lessons 
contain nothing artificial, their practical worth from an instruc- 
tive standpoint is increased. 

386. Bench ProMem No. 1. — 

Errors — Locks deep. Lever long. Elgin type. Single roller. 

Section A 
Remarks (1) — An inspection of the total locks on each pallet 
proved them deep, but equal. 

Section B 
Alteration (2) — Banked escapement to drop. 
Remarks (3) — Found the drop lock deep on each pallet. 

Section C 
Alteration (4) — Decreased the drop lock on each pallet, and 
rebanked escapement to drop. 

Section D 
Remarks (5) — Learned that the roller jewel scraped past each 
slot corner, passing them with difficulty. 

Section E 
Alterations (6) — Filed away a part of the horns and slot 
corners and repolished same. 

Remarks (7) — The corner test now showed correct freedom 
between roller jewel and each slot corner. The angular test 
proved the parts well matched. 

Section F 
Alteration (8) — Spread the bankings for slide. 

Remarks (9) — The changes made greatly improved the es- 
capement. In this instance the readjustment of the guard pin 
to the table gave no trouble. 



153 

LESSON 91 



LIGHT LOCKS— ELGIN TYPE— SEVEN 
JEWELED 



387. Bench ProMem No. 2.— 

Section A 

Remarks (1) — The watch was recently cleaned, but stopped 
while on the rack. 

Section B 

Alteration (2) — Banked escapement to drop. 

Remarks (3) — Found the locks unsafely light for this grade 
of watch. No freedom was discovered by either guard or corner 
tests. The lack of guard and corner freedoms alone prevented 
tripping. 

Section C 

Alterations (4) — Slightly increased the drop locks and re- 
banked to drop. 

Remarks (5) — Result of altering the locks. The guard and 
corner freedoms became correct, and the angular test showed the 
lever's length as matching the locks. 

Section D 
Alteration (6) — Opened the bankings for slide. 
Remarks (7) — The watch gave no further trouble. 



LESSON 92 



BUTTING ERROR— ELGIN TYPE— SINGLE 
ROLLER 



388. Bench Problem No. 3.~ 

Section A 
Remarks (1) — The owner complained about the irregular 
timekeeping qualities of the watch. 



154 

Section B 
Remarks (2) — The locks appeared correct. By the angular 
test the parts were well matched. The corner test showed correct 
corner freedom. The guard test showed the guard pin Inclined 
to stick or butt against edge of table. 

Section C 
Alterations and Remarks (3) — Banked escapement to drop, 
then tried adjusting guard pin. Succeeded in overcoming the 
butting, but the guard freedom was now deficient. 

Section D 
Alteration (4) — Placed the table in lathe, and slightly re- 
duced its size. 

Remarks (6) — Replaced all parts in position and found that 
the guard freedom was correct. The butting error had dis- 
appeared. 

Section B 
Alteration (1) — Opened the bankings, adding slide. 
Remarks (8) — Watch very satisfactory. 



LESSON 93 



SINGLE ROLLER— ELGIN TYPE— ERRORS, 

LONG LEVER AND ROLLER TABLE 

TOO SMALL 



389. Bench Problem, No. 4.— 

Section A 
Remarks (1) — When the watch was received for repairs its 
apparent condition was fair, but the balance had a poor motion. 
Alteration (2) — Banked escapement to drop. 
Result (3) — Found the drop locks correct. 

Section B 

Remarks (4) — Replaced balance, placing the roller jewel in 
the slot. 

Result (5) — Learned that the roller jewel was unable to 
leave the slot. 



155 

Remarks (6) — Two facts are plain — (a) the drop locks are 
correct; (b) the roller jewel is held in the slot. 
Inference (7) — The lever is too long. 

Section C 

Alteration (8) — Reduced the lever's acting length enough to 
allow the roller jewel to pass out of the slot. 

Tests and Alteration (9) — Made use of the corner test to 
still further reduce the lever's acting length and secure the cor- 
rect amount of corner freedom. The length of the lever was con- 
firmed by the angular test. 

Section D 

Remarks (10)— With the guard pin straight too much free- 
dom existed between guard pin and table. 

Alteration (11) — The guard pin was made question mark in 
shape to secure the correct guard freedom. 

Section E 
Alteration (12) — The addition of slide then placed the es- 
capement in good running order. 



LESSON 94 



ERROR, DEFECTIVE ENTRY OF TOOTH ONTO 
PALLET'S IMPULSE FACE 



390. Bench Problem No. 5.— 

Remarks (1) — The owner of this watch complained that it 
gave very poor service. Every six months or so it was in some 
repair shop. After repairing — which the owner said "usually 
was termed cleaning" — it rendered fair service, but soon de- 
teriorated. 

The Tests (2) — The tests showed a normal condition of the 
parts. 

The Defect (3) — The defect present was due to the irregular 
action of the lifts of tooth and pallet. In this escapement, when 
unlocking took place, the pallet corner acted on the impulse face 
of the tooth. 

Remarks (4) — When the lifting actions are correct (see 
former explanations) the tooth corner slips on to the pallet jewel's 
impulse face. 



156 

Alteration (5) — Changed the lifts to conform with Re- 
marks (4). 

Remarks (6) — After a year's service the owner reported the 
watch as "excellent." 



LESSON 95 



ERROR, WANT OF INSIDE SHAKE 



391. Bench Problem No. 6.— 

Remarks (1) — Some watch repairer had lately overhauled the 
watch. Since that time, as the owner expressed it, the watch 
had "stopping fits." 

Inspection (2) — The balance was removed and, while in- 
specting the locks, it was noticed that the drops were irregular. 
The inside drop and inside shake being deficient, especially the 
latter. 

Alteration (3) — As the pallet jewels bore evidence that they 
had been tampered with, a change was made. The locks were 
los3ened and pallets spread slightly. 

Remarks (4) — The effect of alterations were: A correct 
lock, and the drops equalized, besides a safe amount of shake 
inside and outside was secured. Result stoppage did not again 
take place. 



LESSON 96 



SINGLE ROLLER — ELGIN TYPE — ERRORS, 

DEEP LOCKS, RADIUS OF GUARD PIN 

LONG, LEVER LONG 



392. Bench Problem No. 7. — This was an old watch of cheap 
construction and low grade. It was given to a beginner in escape- 
ment work, the instructions being to put same in order. The 
following took place: 



157 

The Lochs — The locks according to the student's observation 
were exceptionally deep. 

The Angular Test — The student next used the angular test, 
neglecting the precaution of bending the guard pin away from the 
table. This test showed each tooth as discharged from each 
pallet. The student then hastily assumed the discharge of the 
teeth implied that the lever's acting length was long. Acting on 
this supposition, the lever's length was made shorter, and thereby 
totally ruined. 

EscapemenVs Real Condition — The total locks, as afterwards 
determined, were excessively deep. The drop locks were correct 
in amount, the excess being entirely attributable to slide. 

According to previous instructions, when the angular test 
Is used it is wisest for beginners to bend the guard point out of 
the way. This student failed to follow instructions and, as the 
guard point was too far forward, it came into contact with the 
table, helped move the lever, and in consequence the angular test 
showed the teeth as discharged. 

For want of a little precaution a new lever had to be fitted. 
You will avoid trouble and erroneous conclusions by banking 
every escapement to drop that you desire to test, and until thor- 
oughly familiar with the angular test remove the guard pin from 
the table. 



158 



LESSON 97 



OUT OF ANGLE— CAUSE, BENT LEVER 



393. Bench ProMem No. 8. — 

Section A 

Alteration (1) — Banked escapement to drop. 

Remarks (2) — Result of Alteration (1). The locks were found 
to be irregular, one lock being greater than its fellow. 

Inspection (3) — Inspected the lever and discovered it was 
bent. 

Section B 

Alterations (4) — ^Without further examination the lever was 
made straight, and escapement was rebanked to drop. 

Remarks (5) — Straightening the lever equalized the drop 
locks and placed the escapement "in angle." 

Section C 
Alteration (6) — Slide, a very necessary feature of every 
normal escapement, was then added. 



LESSON 98 



OUT OF ANGLE— LOCKS IRREGULAR- 
ELGIN TYPE 



394. Bench ProUem No. 9.— 

Section A 
Alteration (1) — Banked escapement to drop. 
Remarks (2) — Found drop locks irregular. The lock on one 
stone exceeding the lock on opposite stone. 



159 

Section B 

R\..marks (3) — Replaced balance. 

Remarks (4) — Rotated balance and learned that the roller 
jewel could pass one slot corner, but was unable to get past the 
opposite corner. 

Remarks (5) — ^We have discovered two things — drop locks 
irregular and a defective relationship of the roller jewel with 
the slot corner. The indications point to the escapement as 
out of angle. 

Section C 

Test (6) — Tried the angular test. To do so had to open out 
one banking — see Remarks (4). Result, contact of one tooth with 
its pallet jewel. The opposite tooth was discharged. Here we 
again find additional evidence that the escapement is out of angle. 

Remark (7) — ^All tests unite in declaring the escapement is 
out of angle. 

Section D 

Alteration (8) — Made the drop locks equal, and rebanked 
escapement to drop. 

Remarks (9) — Equalizing the locks placed the escapement In 
angle, as shown by corner, guard, and angular test. 

Section E 
Alteration (10) — Spread the bankings to provide slide. 



LESSON 99 



OUT OF ANGLE— LOCKS DEEP AND IRREGU- 
LAR—LEVER BENT— ELGIN TYPE 



395. Bench Problem No. 10. — 

Section A 
Alteration (1) — Banked escapement to drop. 
Remarks (2) — Personal inspection of the locks showed they 
were deep and irregular. Also the lever is bent. 

Section B 
Alterations (3) — Straightened the lever and rebanked escape- 
ment to drop. 

Remarks (4) — The locks still remain deep and irregular. 



160 

Section C 

Test (5) — Tried the guard test and found the guard freedoms 
unequal. 

Test (()) — By the corner test, the corner freedoms were proven 
to bo unequal. 

licm.arks (7) — The irregular locks and the unequal corner 
and guard freedoms all confirmed the escapement as being out 
of angle. 

SlOCTION D 

Alteration (H) — The pallet stones were reset, making drop 
locks lighter. 

Alteration (9) — Resetting the pallet stones necessitated bank- 
ing the escapement to drop. 

Remarks (JO) — The drop locks are now correct. The corner, 
guard, and angular test all prove that the escapement is satis- 
factory. 

Section E 

Alteration (JJ) — The banking pins were next adjusted to 
provide the necessary slide. 



LESSON 100 



ERRORS— LOCKS AND DROPS IRREGULAR 
—DRAW BAD 



396, Bench Problem No. 11. — "For some months the watch 
had been out of a repair shop," so the owner said. It was brought 
in for want of accuracy, its timekeeping qualities being poor. 

When the escapement was banked to drop, a difference in the 
locks and the drops was noticed. On the entering pallet the draw 
was very poor, as proven by the fact that the lever when lifted 
away from its bank would remain in position, showing no tend- 
ency to return to its bank. Whenever in the course of usage, a 
shock threw the lever off its bank contact of the guard point and 
table was Inevitable. This, of course, spoiled the timekeeping. 

To correct this defect the entering pallet stone was given a 
greater slant, its end being tilted away from the opposite pallet. 
This change greatly improved the draw, the locks, and the drops, 
besides improving the action of the tooth over tho pallet's im- 
pulse face. 



161 

LESSON 10 



SINGLE ROLLER — ELGIN TYPE — ERRORS, 
DEEP LOCKS— CURVE OF HORNS 



397. Bench Prohlcm No. 12. — This watch had seen Bcrvico 
for probably thirty years. Its general appearance was dilapi- 
dated. 

Our first observation happened to bo of the extent of the 
lever's motion from bank to bank, the bankings being widely 
apart. By placing a finger on the balance and guiding it back and 
forth it was learned that the drop locks were deep. The dial 
was then removed and the excessive depth of the locks confirmed. 
Without further investigation the watch was taken apart and 
the drop locks made correct. 

After correcting the locks and reassembling the watch the 
escapement was banked to drop and the angular test applied. 
As its findings were satisfactory, wo considered the parts as 
matched. 

The guard pin was found to be somewhat close to the table, 
but by manipulating it, correct freedom between pin and table 
was established. 

The curve test was next tried. It was then discovered that 
owing to the shape of the upper parts of the horns the roller 
jewel would catch on their tips. To overcome this defect the 
end of each horn was changed in shape. 

The necessity for changing the shape of each horn is at- 
tributable to the altered position of the guard pin. Slide was 
then provided, which completed the operation. 



LESSON 102 



DOUBLE ROLLER — ELGIN TYPE r— ERRORS, 
LIGHT LOCKS AND A CORNER TRIP 



398. Bench Problem No. 13.~ 

Section A 
Remarks (1) — This watch was recently purchased. The 
owner returned it, complaining that its timekeeping qualities 
were uncertain. 



162 

Alteration (2) — Banked escapement to drop. 

Section B 
Remarks (3) — Banking the escapement to drop brought out 
two defects — (a) that the drop locks were unsafely light; (b) on 
replacing the balance no freedom whatever existed between the 
guard point and safety roller. 

Remarks (It) — The fact that the guard point was in close 
contact with the edge of the table acted as a preventive of 
tripping. 

Section C 
Test (5) — The corner test was next employed. Result of this 
test: A slight amount of corner freedom was found. 

Remarks (6) — ^As slight as the corner freedom was, it allowed 
the escapement to trip. The tripping error was evidently due to 
the unsafely light locks. 

Section D 
Alterations (7) — Increased the drop locks and rebanked 
escapement to drop. 

Section E 
Test (8) — The corner and guard tests were again used, each 
now showed freedom and an absence of any tendency towards a 
tripping error. 

Section F 
Alteration (9) — The addition of slide placed the escapement 
in good order. 



LESSON 103 



SINGLE ROLLER— MOVEMENT MARKED AD- 
JUSTED—ELGIN TYPE— ERRORS, DEEP 
LOCK, LONG LEVER, TABLE 
DIAMETER LARGE 



399. Bench Problem No. IJf. — 

Section A 

Remarks (1) — This was a new movement and was examined 
because of the large total lock it possessed. The total lock ap- 
proached 6 degrees, as judged by the table in Paragraph No. 183. 

Alteration (2) — Banked escapement to drop. 



163 

Remarks (3) — On banking to drop it was learned that the 
drop lock approximated 4 degrees. Evidently the slide amounted 
to about 2 degrees. 

Section D 

Remarks (4) — Decided to try the angular test. 

Test (5) — The angular test proved the parts matched — 
namely, the lever's length was suited to the deep lock. 

Remarks (6) — ^Although the angular test showed the parts 
as matched, the deep lock could not be allowed to go uncorrected. 

Section C 
Alteration (1) — Altered the drop lock, making same correct. 
Alteration (8) — Rebanked the escapement to drop. 

Section D 

Alteration (9)— Bent the guard pin away from the edge of the 
table. 

Remarks (10) — It was now discovered that owing to lessen- 
ing of the locks and rebanking to drop, that only with difficulty 
could the roller jewel be brought past the slot corners. 

Remarks (11) — The lack of corner freedoms as above men- 
tioned indicated a change as necessary. 

Section E 

Alterations (12) — To provide corner freedom, cut the horn 
and slot corners away. Frequent use was made of both the corner 
and angular test to prevent an over-reduction of the lever's acting 
length. 

Remarks (13) — In this way the correct corner freedoms were 
secured. The angular test also showed the new drop locks were 
adapted to the lever's altered length. 

Section P 

Alteration (14) — Made the guard pin straight — see Altera- 
tion (9). 

Remarks (15) — The result of straightening the guard pin 
caused contact of pin with table. 

Section G 

Alteration (16) — As a matter of experiment, the bankings 
were opened. 

Remarks (17) — The guard pin, it was then discovered, would 
stick or butt against edge of table. 

Section H 
Alteration (18) — Rebanked escapement to drop. 



164 

Alteration (19) — Placed the roller table in the lathe and 
ground off its edge, thereby reducing its size. 

Alteration (20) — Slightly advanced the guard pin's position. 

Remarks (21) — Replaced all parts in position. Found as 
result of Alterations (19) and (20) that the butting error had 
disappeared, and a correct amount of guard freedom secured. 

Section I 
Alteration (22) — The bankings were next opened for slide. 
Remarks (23) — The watch was timed in positions. It after- 
wards proved an excellent timepiece. 



165 

Index to Hints and Helps 



400. 1. Testing and Altering a Light Lock. 

2. Estimating the Three Safety Locks. 

3. Resetting Pallet Jewels, Method A. 

4. Resetting Pallet Jewels, Method B. 

5. Remarks on Methods A and B. 

6. The Resetting of one Pallet Stone, 

7. Correction of Guard Point and Table Errors. 

8. Irregular contact of Guard Point with Table. 

9. Test for Table Wanting in Truth. 

10. Replacing a Lost Roller Table. 

11. Setting a Roller Jewel to Correctly Match the Es- 

capement. 

12. The Corner Test in Practice. 

13. Calculating Dimensions of a New Escape Wheel. 

14. Replacing Lost Pallet. 



166 

LESSON 104 



HINTS AND HELPS NO. i 



401. Testing and Altering a Light Lock. — ^Among the cheaper 
grades of watches we sometimes encounter a lock that looks sus- 
piciously light. When such is found, and an alteration is desir- 
able it is best to make an exhaustive test covering the entire 
escapement action. Usually an inspection of the drop locks reveals 
that one lock slightly exceeds the other. Should this be the case, 
and an increase of the lesser lock be desirable. Try the guard 
safety test, or the corner safety test, or both. Before making 
any alteration examine and compare the extent of the respective 
safety locks. Do this as a guide towards deciding which is the 
lesser lock. As a further precaution, test the lock of many 
teeth of the escape wheel, for the reason that frequently In 
cheaper watches the length of the escape wheel teeth vary. 

In low grade watches we can best determine whether a light 
lock is satisfactory, or unsatisfactory, by banking the escapement 
to drop, using the angular, corner, guard and safety tests to 
arrive at a definite conclusion. 



LESSON 105 



HINTS AND HELPS NO. 2 



402. Estimating the Three Safety Locks. — The extent of the 
safety or remaining lock should be investigated and estimated in 
three places, as follows: First, by bringing the guard point in 
contact with the edge of the table (guard safety test) ; then, with 
an eyeglass, note the extent to which the tooth remains locked 
on the pallet jewel. 

The second place for making an observation of the safety 
lock is, when the corner of the lever slot is brought in contact 
with the face of the roller jewel (corner safety test). 

The third place in which the safety lock should be estimated 
la when the curve of the horn is brought into contact with the 
roller jewel (curve safety test). The contact mentioned can only 
be obtained when the guard point is within the crescent. 



167 



LESSON 106 



HINTS AND HELPS NO. 3 



403. Resetting Pallet Jewel— Both Pallet Stones put of 
Place — Elgin Type. — 

Note — The problem stated below involves resetting the pallet 
jewels in such a way that the drop lock will be safe, light, and 
adapted to the fork-roller jewel action. When this has been 
attained the escapement will be well matched. 

Should you at any time encounter an escapement in the 
condition mentioned below, do not commence alterations by 
attempting to set the pallet jewels so the lock looks about right, 
because as a rule you will find the suggestions in Methods A and 
B much more desirable. 

In connection with this lesson students are advised to apply 
the instructions in a practical way — namely, obtain a watch, then 
remove the pallet jewels out of their settings and entirely alter 
the position of the banking pins. This done, Methods A and B 
can be used and very practical lessons be learned about resetting 
pallet stones, and in relocating lost positions of the banking pins. 

The following represents the state of the escapement: 

Condition — Both pallet jewels removed from their settings. 
Bankings tampered with, so they are useless as guides. 

Method A (Guard Test) — ^When both bankings have been 
disturbed, and both pallet stones removed, we can by employing 
the following system again locate the positions the bankings will 
occupy when the escapement is banked to drop. This position 
of the bankings being found, it facilitates the resetting of the 
pallet stones. 

Directions — Place the lever and balance in position, next 
turn in each banking so as to bring the guard point nearly in 
contact with the edge of the table (Elgin type). Assuming that 
the location of the banking pins as above determined represents 
the position for correct drop lock, the pallet jewels are reset 
accordingly. If the table's diameter is correct, and the guard pin 
straight no trouble is likely to be experienced. 

Should the table's diameter be too large the result of resetting 
will be a deep lock. On the other hand, if the table's diameter is 
too small the drop lock will be correspondingly light. 



168 

Whenever the drop locks as determined by Method A prove 
unsatisfactory — that is, light or deep — it is then advisable to 
employ Method B as explained in the following lesson. 

Note — If the escapement is of the South Bend type, each 
banking pin must be adjusted so as to bring the guard pin in 
direct contact with the edge of the table. We thereby establish a 
correct position of the bankings, which enables us to reset the 
pallet stones for drop lock only. 



169 



LESSON 107 



HINTS AND HELPS NO. 4 



404. Resetting Pallet Jewels — Both Pallet Stones Out of 
Place — Elgin Type. — 

Note — The state of the escapement is exactly the same as In 
the previous lesson. 

Conditions — Both pallet jewels removed from their settings. 
Position of banking pins so altered they are useless as guides. 

Method B (Corner Test) — ^As before, the problem is to reset 
the pallet stones so the drop lock will be light yet safe, and also 
adapted to the action of the roller jewel with the fork. 

To make use of Method B, place the lever and balance in 
position, next revolve the balance so as to bring the roller jewel 
opposite the corner of the lever slot, then hold balance in this 
position and adjust each banking pin so as to establish a slight 
freedom between the slot corner and face of roller jewel. With this 
position of the banking pins as a guide the pallet stones are 
reset for drop lock only. 

If owing to some disturbing element in either the acting 
length of the lever or the location of the roller jewel we obtain 
in place of a correct lock, a lock that is deep, we realize that the 
lever's length is too long or that the roller jewel is too far for- 
ward. Should the drop lock obtained by Method B result in 
establishing a drop lock that is too light we then know that either 
the lever is short, or the roller jewel is not sufficiently forward. 

A failure to obtain a correct drop lock by Methods A and 
B mean that the escapement is mismatched and that alterations 
will have to be made to improve the escapement. (See following 
lesson.) 



170 



LESSON 108 



HINTS AND HELPS NO. 5 



405. Remarks on Methods A and B. — When Methods A and B 
fail us we must then depend on sight and judgment to reset the 
pallet jewels so as to provide a drop lock suitable for that par- 
ticular escapement. With some assumed standard of correct lock 
present we then fall back upon the corner, guard and angular 
tests. Alterations must be made in accordance with the instruc- 
tions given in the test lessons. You may feel certain that the 
parts are very much mismatched when Methods A and B fail to 
yield satisfactory results. 



LESSON 109 



HINTS AND HELPS NO. 6 



406. The Resetting of One Pallet Stone — Elgin Type. — Given 
an escapement with one pallet stone remaining in its original 
position, the opposite pallet jewel being out of place, and we 
desire to reset the loose stone in conformity with the stone still 
in place, we can for this purpose make use of one or both of the 
following methods. No trouble will be experienced unless the 
escapement is mismatched; if so, the test lessons should be 
consulted and suitable alterations made. 

Guard Test Method — Turn in the bankings so the guard point 
nearly but not quite touches the edge of the table. With this 
new position of the bankings as a guide, set the loose pallet jewel 
for drop lock. 

Corner Test Method — Close in the bankings to such an extent 
that when the corner test is applied a slight freedom is found 
between the slot corner and the roller jewel. With the bankings 
established in this position the pallet stone should be reset for 
drop lock. 



171 



LESSON no 



HINTS AND HELPS NO. 7 



407. Correction of Guard Point and Table Errors. — 
Note — The purpose of this lesson is to call attention to some 
practical and useful point. Although some of them have been 
previously mentioned, the gathering together of these items will 
add to their usefulness. 

Contact of Guard Point and Table. — When a watch of the 
Elgin type is banked to drop and we discover contact of the 
guard point with both sides of the table the remedies to be 
applied are as follows: 

A. Replace old table with a new one of lesser diameter. 

B. Continue the use of the old table, but lessen the diameter 
of the guard point. (Methods A and E are usually preferable.) 

The suggested reduction of the thickness of the guard point 
is best done in single-roller escapements by means of a tool made 
to slip over the guard pin. The work of the tool is to thin the 
guard pin by shaving its front and sides. Such a tool can be 
made from a medium sized needle. A hole should be drilled in it 
slightly larger and deeper than the guard pin. After drilling, the 
hollow circular end of the tool should be sharpened. In order to 
prevent the tool clogging when in use, a part of the back as far 
in as the beginning of the hole should l3e filed away for clearance. 

C. If we think it desirable to continue the use of the old 
table, the guard pin can be bent away from the edge of the table. 
The belly caused by bending can frequently be removed by the 
tool above described. If the belly is too great, better lessen 
the diameter of the old table and keep the guard pin upright. 

D. The insertion of a new but slightly tapering pin at times 
helps to lessen the trouble. 

E. The diameter of the table can be lessened by securing it 
in the lathe and turning it down a trifle. This will provide the 
required freedom. A lap for grinding the table's edge is superior 
to the graver. 

F. If the Methods B, C, or D, result in a hutting action of the 
guard point with edge of table, the butting error must be elim- 
inated by the use of the remedies suggested in A or B. 



172 



LESSON 111 



HINTS AND HELPS NO. 8 



408. Irregular Contact of Guard Point with Table. — If we 
suspect or know that the guard point touches the edge of the 
table in some places and is free in others, it indicates: 

A. The table is out of truth in the round. 

B. The balance pivots may be bent. 

C. Pivots working in holes too large for them. 

D. Dirt or shellac about the edge of the table. 

B. Roughness on the edge of the table. It is advisable to 
polish the edge of a table that appears rough. 



LESSON 112 



HINTS AND HELPS NO. g 



409. Test for Table Wanting in Truth. — First, close in one 
banking so the guard point barely touches the edge of the table; 
second, slowly rotate the balance; third, find out, by frequently 
trying the shake, where contact takes place and where the guard 
point has more or less freedom from edge of table; fourth, as 
regards the correction required, find the cause of the trouble 
and correct it. (Consult previous lesson.) 



173 



LESSON 113 



HINTS AND HELPS NO. lo 



410. Replacing a Lost Roller TaMe. — As the principles in- 
volved in the selection of new tables for a double roller escape- 
ment are identical with the principles governing the selection of 
a new table for a single roller escapement, we shall treat the 
subject from the standpoint of the latter. 

Assuming we have in hand a single-roller escapement of the 
Elgin type whose drop locks are correct, the following is the 
procedure in supplying a new table. There are two points calling 
for attention — namely, the diameter or distance across the table 
and the position of the roller jewel. These are the governing 
features: 

Operation A — Bank the escapement to drop. 

Operation B — Select a table of such a size that a little free- 
dom or space is left between the guard pin and edge of table. 
(The guard freedom of the guard test.) 

Operation G — The position of the roller jewel must be such 
that a little freedom is found between roller jewel and the slot 
corners. (Corner freedom.) 

To confirm the correctness of the table's dimensions and 
position of roller jewel, make use of all the safety tests and also 
employ the angular test. 

Should there exist any tendency of the guard point to butt 
or stick against the edge of the table, the test lesson on a butting 
error should should be consulted. We wish also to call your 
attention to the fact that we stated in our opening paragraph 
that the drop locks were correct, hence if you discover any de- 
fects in the locks make the necessary alterations previous to 
fitting a new table. 



174 



LESSON 114 



HINTS AND HELPS NO. ii 



411. Setting a Roller Jewel to Correctly Match the Escape- 
ment. — When replacing a lost or loose roller jewel, pay careful 
attention to size and position. A roller jewel should be fitted to 
the fork slot and not to the hole in the table. Select a jewel 
allowing of a slight side play in the slot. If the side play is too 
great the lever will "jump." This jumping of the lever is easily 
detected by placing a finger on the balance rim, and slowly 
guiding the roller jewel into the slot. A roller jewel which 
allows the lever to jump is either too small for its slot or is loose. 
If too small it must be replaced by a wider jewel, because a roller 
jewel too small for its slot deranges the entire escapement action. 

The position the roller jewel occupies in the table is of 
great importance. The holes in many tables are too large. When 
we encounter tables with large holes we must, in order to obtain 
the correct location of the roller jewel, be guided by the findings 
of the angular and corner tests, the latter test being used with 
the escapement banked to drop. 

If we desire to set a roller jewel in an Elgin escapement of a 
"correct type," it is necessary to provide a little freedom between 
the slot corners and the roller jewel, as required by the corner 
test under banked to drop conditions. In this way a correct roller 
jewel radius is obtained. 

If we bank an escapement of the South Bend type to drop, 
then, according to the rules controlling this type of escapement, 
when a roller jewel is correctly placed the corner test will show 
that the roller jewel just touches the slot corners as it passes in 
or out of the slot. This distinction between the escapement types 
must be borne in mind. 



175 



LESSON 115 



HINTS AND HELPS NO. 12 



412. The Corner Test in Practice. — The following method of 
using the corner test possesses many practical advantages. The 
description given applies to the test in two forms — first, banked 
to drop; second, not banked to drop. When it is undesirable to 
disturb the position of the bankings the latter method proves very 
useful. 

The amount of corner freedom when an escapement is not 
banked to drop always exceeds the amount of corner freedom 
when the escapement is banked to drop. The excess is of course 
attributable to the presence of slide. 

When using this test without banking the escapement to 
drop, if a seeming surplus of corner freedom is experienced, the 
extent of slide should be investigated, and mental deductions 
made of the slide from the excessive corner freedom. 

If we discover a great deal of corner freedom when the slide 
is not excessive, we realize that something is wrong and correc- 
tions are called for. Anything of this nature that is found must 
be investigated, and corrections if they are necessary should be 
made. As an added help in the detection of errors relating to 
our subject it will be found useful to compare the amount of 
guard pin freedom with the corner freedom. These should be 
about equal, as elsewhere explained. 

Corner Test Not Banked to Drop — First — Revolve the balance 
so as to bring the roller jewel well past the end of the horn, and 
hold it there. 

Second — Place a watch oiler or other fine tool against the 
side of the lever in such a way that the lever is securely held 
against its bank. 

Third — Remove finger from balance. 

Fourth — Result of releasing the balance is, the roller jewel 
immediately bounds into slot. 

Fifth — When the roller jewel settles against the opposing 
wall of the slot, again place your finger on the balance rim, being 
careful not to move the balance the slightest. 

Sixth — ^While the balance is being held steady and secure, 
change the watch oiler, or other fine tool, to the opposite side of 



176 

the lever, and try how much you can lift the lever away from its 
bank. 

Seventh — The extent ^the lever can be moved away from its 
bank represents the amount of freedom present between the slot 
corner and the roller jewel. 

Corner Test Banked to Drop — The above instructions should 
be followed out in detail. The only difference experienced will 
be that with the escapement banked to drop a lesser amount of 
corner freedom is found. 



177 



LESSON 116 



HINTS AND HELPS NO. 13 



413. Calculating Dimensions of a New Escape Wheel. — 

English Ratchet Tooth Escape Wheel — If an escape wheel 
with ratchet shaped teeth is lost, the size of a new one is cal- 
culated as follows: 

Rule — (a) Measure the distance of centers between hole for 
pivot of escape pinion and hole for pivot of pallet staff. 

(b) Multiply the distance the center of these holes are apart 
by .866. The product is the radius of the new wheel. 

Example — If the distance of centers equals 3.6 millimeters 
determine the radius of an escape wheel with ratchet teeth 
adapted to this distance. Following the rule stated above: 
3.6 X .866 = 3.11 millimeters. 

As answer shows the radius of the new wheel will measure 
3.11 millimeters. 

If we take a depthing tool and adjust the points to 3.11 
millimeters apart and place one point of the tool in center of 
wheel, the other point will touch the tips of the teeth, provided 
the wheel is correct in size. 

Fine measuring tools are desirable, such as guage 1/100 of a 
millimeter or 1/1000 of an inch. Most watchmakers own tools 
registering 1/10 millimeters, and on the principle that some 
idea of size is preferable to none we suggest they use such guages 
for measuring center distances and calculating sizes of escape 
wheels. A few practical experiments will demonstrate that calcu- 
lations are not at all difficult. 

Cluh Tooth Escape Wheels — The selection of an escape wheel 
with club teeth requires tv/o sets of calculations, both easily 
made. 

If the reader turns to Fig. 10, he will see that to draft a 
club tooth escape wheel requires an inner and an outer circle. 
Upon the inner circle the locking corners of all teeth will rest. 
Upon the outer circle the points of the teeth come in contact. 
To determine the size of a club tooth escape wheel we must figure 
the radius of each circle as it relates to their common distance 
of centers. 

Radius of Inner Circle — Rule A 1 — Multiply the measure of 



178 

the distance of centers by .866. The product will be the radius 
of the inner circle. 

Radius of Outer Circle — Rule — Multiply the measure of the 
distance of centers by the modulus representing the angle of lift 
on tooth. (See following table.) 

Moduli for Radius Outer Circle — 

Lift. Modulus. 
3° = .892 
3%° = .894 
31/2" = .896 
33/4° = .898 
4° = .900 
Question — Given a distance of centers, as 3.6 millimeters, and 
lifting angle on tooth as 3 degrees, (a) determine the radius of 
the inner circle (C. C, Fig. 10) ; (b) also determine the radius of 
the outer circle. (00, Pig. 10.) 

Calculating Radius Inner Circle — 

Center distance 3.6 
Modulus .866 

3.6 X .866 = 3.11 
Radius of inner circle measures 3.11 millimeters. 
Calculating Radius of Outer Circle — 

Distance of centers 3.6 
3° of lift. Modulus .892 
3.6 X .892 = 3.21 
The radius of the outer circle equals 3.21 millimeters. 
In this manner the dimensions of any club-tooth escape wheel 
may be worked out. The modulus for any lift can be learned by 
turning to a table of tangents — for instance, the tangent of 3 
degrees is .05241, divide this by 2 and we get .02620, adding it to 
.866 gives .892, as the modulus, which when multiplied by the 
distance of centers tell us the radius of the outer circle. 

If the lift is 4 degrees its tangent is .06993, dividing by 2 
yield .03496, adding this to .866 produces .900, the last modulus 
in the foregoing table. 

Checking Sizes of Escape Wheels in Drawings or Models— 
The method just explained can be used to practical advantage in 
verifying the size of an escape wheel in a drawing or in an 
escapement model. 



179 



LESSON 117 



HINTS AND HELPS NO. 14 



414. Replacing Lost Pallets. — Owing to the extent of this 
topic, we shall confine our remarks to a few brief rules capable of 
easy application. 

Replacing Equidistant Pallets — To obtain the measure of 
the distance between pallet center and locking corner of each 
pallet jewel: 

Rule — Multiply the measure of the distance between pallet 
and balance centers by .5. The answer will represent the meas- 
ure of the distance between pallet center and locking corner of 
each pallet jewel. 

Example — Calculate for equidistant pallets the distance sep- 
arating the pallet center to the respective locking corners of each 
5. X .5 = 2.5 millimeters 

The locking corner of each pallet jewel will be 2.5 milli- 
meters from the pallet center. 

To find the measure of the distance separating the letting- 
off corners of each pallet jewel from center of pallet staff would 
rnvolve us in questions of width and lift, subjects too great for 
present consideration. 

Replacing Circular Pallets — Without full knowledge of widths 
and lifts it is not possible to calculate the measure of the dis- 
tance between pallet center and either the locking or letting off 
corners of circular pallets. What is possible and easy to follow 
is to calculate the measure of the distance from the pallet center 
to a point midway between locking and letting off corner of either 
pallet stone — viz., to center of pallet jewel. We can make use of 
such information as a guide. This and the practical knowledge 
outlined in the lessons will solve the problem of supplying a new 
lever. 

Rule — Measure the distance of centers between pallet and 
balance staff and multiply same by .5. 

Example — If in an escapement with circular pallets the dis- 
tance of centers is 5. millimeters, what is the measure of the 
distance between the pallet center and center of each pallet 
Jewel? 



180 

5. X .5 = 2.5 millimeters. 
The center of each pallet stone will be 2.5 millimeters from 
the pallet center. Students possessing drafts of the escapement 
can apply practically the rules given. 



Index to Facts Practical and Theoretical 



415. 1. Angular Motion of Lever and Impulse Angle of 
Roller Jewel. 

2. A Practical Method of Estimating Degrees of Lever's 

Angular Motion, the Locks, the Lifts and Impulse 
Angle of Roller Jewel. 

3. Proportional Method of Calculating the Lever's 

Acting Length, and Roller Jewel Radius. 

4. Theoretical and Practical Radius of the Roller 

Jewel. 

5. Given Degrees of Lever's Angular Motion and of 

Impulse Angle; to Calculate Theoretical and 
Practical Radius of Roller Jewel and Lever's 
Acting Length. 

6. The Division of the Lifts with Regard to the Width 

of Pallet and Tooth, and Tooth Freedom from 
Pallet Center. 

7. Freedom of Tooth's Heel from Pallet Center. 



181 



LESSON 118 



FACTS PRACTICAL AND THEORETICAL NO. i 



416. Angular Motion of Lever and Impulse Angle of Roller 
Jewel. — The motion of the lever from bank to bank is known as 
the lever's angular motion. It is composed of the locks and 
lifts. The extent of angular motion is least when an escapement 
is banked to drop and greatest when slide lock is present. It is 
more desirable to make calculations when the extent of angular 
motion is least. The angular motion of the lever is a varying 
quantity, usually from 10 degrees to 12 degrees measured from 
the pallet center. 

Roller JeweVs Impulse Angle — ^When the roller jewel during 
its routine of rotation meets the slot it remains for a short 
period in contact with the same. The extent of contact of the 
roller jewel with the slot is known as the roller jewel's angle ot 
impulse. As the center of the balance corresponds with the 
center of the circle described by the roller jewel, the degrees oi 
contact of roller jewel with fork slot are measured from the bal- 
ance center. Generally speaking, the impulse angle of the roller 
jewel varies from 28 to 48 degrees. In double roller escapements 
from 28 to 35 degrees represents the impulse angle. The lesser 
the impulse angle the greater the detachment of the roller jewel 
from the fork. It can therefore be understood why a well cou' 
structed double roller escapement possesses an advantage over 
single roller escapements. 



182 



LESSON 119 



FACTS PRACTICAL AND THEORETICAL NO. 2 



417. A Practical Method of Estimating Degrees of Lever^s 
Angular Motion, the Locks, the Lifts and Impulse Angle of 
Roller Jewel. — In a simple manner — namely, by means of a pro- 
tractor — we can with a fair amount of accuracy determine the 
number of degrees contained in the lever's angular motion, the 
impulse angle, and separately the locks and lifts. Experiments 
of this nature are recommended because they impress the stu- 
dent's mind in a very practical way with facts regarding the 
origin and relationship of the various angles. 

The Protractor — For the purpose of these experiments, attach 
a short upright pin exactly at the center of the protractor. This 
pin should extend about one-fourth of an inch above the surface 
of the instrument, the tip of the upright to be so formed that its 
point fits snugly into the cup or oilsink of the pallet jewel. If 
we shorten the pivot of the pallet staff the point of the upright 
pin can be shaped into a stubby cone pivot capable of entering 
the pallet jev/el hole. By this latter method greater accuracy in 
the measurement of the degrees is possible. 

The Escape Wheel — To prepare the escape wheel so the de- 
grees of lift on the pallet's impulse face can be measured neces- 
sitates filing the lift from one tooth. The cutting should exteni? 
as far as the tooth's locking corner. When finished the tooth 
will be wedge shaped, resembling a tooth of an escape wheel 
having ratchet teeth. 

The Lever — To the lever bar we must attach an index pointer 
of brass wire, shaping it so it clears the bed plate, and long 
enough to reach the degree marks on the protractor. If the 
escapement is to be kept for the purpose of demonstrating the 
lifts and locks, the index arm can be soldered to the lever bar. 
This makes the arm rigid. Should we not desire to sacrifice the 
lever it will be necessary to find another way of attaching the 
arm to the lever bar, utilizing the guard pin to steady the pointer. 

Testing Lever's Angular Motion — For experimenr;, a 16-S!ze 
bridge model is desirable, because the parts are visible and 
accessible. The index arm being attached to the bar, place the 
lever and escape wheel in the movement. As the angles relating 



183 

to the motion of the lever are measured from the pallet center 
we place the cup or oilsink of the pallet jewel on top of the 
upright point attached to the center of the protractor. Place the 
lever against its bank and note the degree mark covered by the 
index arm; next shift the lever to its opposite bank and count 
the number of degrees the index pointer passed over (banked to 
bank). The number of degrees thus counted represents the 
lever's angular motion. 

Measuring the Lock — To measure the degrees of lock, place 
the lever against its bank, then note the degree mark the index 
arm stands over; next move the lever so the tooth of the escape 
wheel is brought down to the lowest locking corner of the pallet 
jewel; again read the degree scale and thereby determine the 
degrees of lock. In this manner we can estimate both the slide 
and drop lock. 

Measuring the Total Lift — The degrees of lift on tooth and 
pallet combined can be found by passing their combined lifting 
planes over each other. 

Measuring Lift on Pallet — The number of degrees of lift on 
the impulse face of the pallet can be ascertained by passing the 
ratchet tooth which we prepared for this purpose over the pallet 
jewel's lifting plane. 

Measuring Lift on Tooth — The lift on the pallet subtracted 
from the total lift of pallet and tooth will give the degrees of lift 
on the tooth. 

Measuring the Impulse Angle — To estimate the number of 
degrees of the impulse angle, prepare a point for the protractor 
which closely fits into the recess in the cap jewel of the balance. 
It is also necessary to insert into a screw hole of the balance rim 
an index pointer of suflacient length to reach the degree scale of 
the protractor. It is then an easy matter to read from the scale 
the degrees of contact of the roller jewel with the fork slot either 
with the escapement banked or not banked to drop. In this way a 
working knowledge of the angles we have been considering can 
be obtained. 



184 



LESSON 120 



FACTS PRACTICAL AND THEORETICAL NO. 3 



418. Proportional Method of Calculating the Lever's Acting 
Length and Roller Jewel Radius. — The angular motion of the 
lever, and the impulse angle of the roller jewel bear a very close 
relationship to each other as regards their distance of centers, 
the acting length of the lever, and the roller jewel radius. 

If we are given the lever's angular motion in degrees, and 
also the degrees representing the impulse angle of the roller jewel 
we can closely approximate the length of the lever and the 
theoretical radius of the roller jewel. If the lever's angular 
motion is 10 degrees and the impulse angle of the roller jewel is 
30 degrees, the ratio of the angle is 10 to 30 or 1 to 3. The 
ratio of 1 to 3 approximately indicates that for every three milli- 
meters or parts contained in lever's acting length, the radius of 
the roller jewel should contain one. If the lever's acting length 
Is 6 millimeters, the roller jewel radius, according to statement 
just made, should be 2 millimeters. 

If we are given both angles and the lever's acting length we 
can by proportion approximate the radius of the roller jewel. 

Example — The angles are 12 and 48 respectively, the lever's 
acting length is 8 millimeters; calculate therefrom the roller 
jewel's theoretical radius — by proportion 48 : 12 : 8, multiplying 
the second and third terms together and dividing by the first 
we obtain 2 millimeters as the theoretical radius of the roller 
jewel. 

Given the radius of the roller jewel as 1.8 millimeters, and 
the angles as 10 and 35, calculate the lever's acting length. As 
before, we make use of proportion: 

10 : 35 :: 1.8 
35. X 1.8 = 63.0 
63.0 ^ 10 = 6.30 

The lever's acting length is 6.3 millimeters. 

If we know the lever's acting length and the theoretical 
radius of the roller jewel we can closely approximate the ratio 
of the lever's angular motion to the roller jewel's impulse angle. 



185 

The rule is, divide the radius of the roller jewel into the length 
of the lever. 

Example — The acting length of a lever is 4. millimeters and 
the theoretical radius of the roller jewel is 1.33 millimeters — 
determine the ratio of their angles. 

4 -^ 1.33 = 3 
1.33 -T- 1.33 = 1 
The ratio of the angle is approximately 1 to 3 or as 10 to 30. 



186 



LESSON 12 



FACTS PRACTICAL AND THEORETICAL NO. 4 



419. Theoretical and Practical Radius of the Roller Jeioel. — 
The practical radius of the roller jewel always exceeds the roller 
jewel's theoretical radius. Increasing the theoretical radius by 
from 5 to 8 per cent, should, if the escapement is well planned, 
give the length of the practical radius. 

If we construct an escapement and allow the roller jewel only 
its theoretical impulse radius, the roller jewel will, when in 
action, strike exactly on the slot corner. To overcome this defect 
the radius is made longer, thereby enabling the roller jewel to 
strike the wall of the slot and to conserve its action entirely 
within the slot. 



LESSON 122 



FACTS PRACTICAL AND THEORETICAL NO. 5 



420. Given Degrees of Lever's Angular Motion, and of Im- 
pulse Angle to Calculate the Theoretical and Practical Radius of 
Roller Jewel and the Lever's Acting Length. — In order to follow 
out the below calculations, a book on trigonometry, containing 
tables of signs, is necessary — this, and a knowledge of multipli- 
cation and division of decimals, is all that is required to solve 
like problems. The system here outlined will be found more 
accurate than the preceding instruction by the proportional 
method, but more figuring is required. 

Rules — A. Add together the angle of impulse and lever's 
angle of motion, then divide their sum by 2 and by means of the 
tables above mentioned find the sine of the answer. 



187 

B. Divide the angle of impulse by 2 and, as before, find the 
sine of the answer. 

C. Divide the sine of the larger angle (Sub Rule B) by the 
sine of the lesser angle (Sub Rule A). 

D. The quotient obtained by means of Sub Rule C should be 
divided into 1. The answer will be the modulus for the lever's 
acting length. 

E. The above modulus multiplied by whatever the distance 
of centers may be will give the acting length of the lever suited 
to the center distance. 

P. The length of the lever as calculated by Sub Rule E 
should next be multiplied by number of degrees representing 
the lever's angular motion and divided by the number of degrees 
contained in the roller jewel's impulse angle. The answer ob- 
tained will be the theoretical radius of the roller jewel. 

G. Multiply the theoretical radius by .05 or ,08 (sometimes 
more) . 

H. Add the product obtained according to Sub Rule G to 
the theoretical radius and answer will be the Practical radius 
of the roller jewel. 

Example — The angular motion of the lever is 10 degrees. 
The angle of impulse is 30 degrees. The distance of centers is 
10 millimeters. Calculate from above data the practical radius 
of the roller jewel. The practical radius being 5 per cent, longer 
than the theoretical. 

Rules— A. 10" + 30° = 40° ^ 2 = 20° 
Sine of 20° = .34202 
Sine of 15° = .25882 

B. 30° -f- 2 == 15° 

C. .34202 -T- .25882 = 1.3215 

D. 1.00 -f- 1.3215 == .7567 lever modulus 

E. .7567 X 10. '= 7.56 lever's length 

F. 7.56 X 10° H- 30° = 2.52 theoretical radius 

G. 2.52 X .05 = .126 

H. 2.52 + .126 = 2.64 practical radius 

According to Sub Rule E the lever's acting length is 7.56 
millimeters and the practical radius as shown by Sub Rule H 
is 2.64 millimeters. As previously mentioned, the length of the 
practical radius is a varying factor. It is somewhat dependent 
upon the specifications especially as regards the division of the 
total lock. 

The following is taken from a large escapement drawing: 

Distance of centers, 290 millimeters. 

Impulse angle, roller jewel, 35°. 

Angular motion of lever, 10°. 



188 

By means of the above, calculate the lever's acting length 
and practical roller jewel radius, allowing the practical an in- 
crease of 7 per cent, over the theoretical radius. 

35° + 10° == 45° 
45° -T- 2 = 221/2° 
Sine of 221/2° = .3827 

35° -- 2 = 17 1-2 
Sine of 171/2° = .3007 
.38027 -f- .3007 = 1.2727 

1. -^ 1.2727 = 227.82 mm. lever's length 
227.82 X 10° -r- 35° = 65.08 mm. theoretical radius 
65.08 X .07 = 4.55 
65.08 + 4.55 = 69.63 mm. practical radius 

The methods outlined for calculating lever's length and radius 
of roller jewel can be applied to advantage in checking drawings 
and models of the escapement. The calculations made also show 
that for different angles the modulus varies, therefore the 
modulus connected with the angles must be known before the 
lever's length can be determined. 



189 



LESSON 123 



FACTS PRACTICAL AND THEORETICAL NO. 6 



421. The Division of the Lifts, With Regard to the Widths of 
Pallet and Tooth — Calculating Tooth's Freedom from Pallet 
Center. — A few words about the divisional relationship existing 
between the width and lifts will be heplful to such as are inter- 
ested in escapement drafting and construction of escapement 
models. As the amount of lift on a tooth, when the pallets are 
planted at the meeting points of the tangents is a corelated sub- 
ject we shall also briefly discuss same. 

No hard-and-fast rule can be followed for the relative pro- 
portions of the lifts to the widths, as a student will learn by- 
investigating the various escapement specifications which come 
before him. A good general rule is to divide the lift as we divide 
the width subject to some modifications; for instance, making 
the tooth three-quarters the width of the pallet. For example, if 
the combined width of tooth and pallet, measured from the escape 
wheel center is IQi/^ degrees. 

We can divide it as follows: 

Width of pallet, 6° 
Width of tooth, 41/2° 

On this basis of the division of the width we shall calculate 
the division of the lifts. Commence by expressing the foregoing 
widths in minutes: 

Total width, 101/2° = 630' 
Pallet width, 6° = 360' 
Tooth width, 41/2° = 270' 

We next figure what per cent, of the total width belongs to 
the tooth. This part of the problem can be solved by proportion 
as follows: 

630 : 270 :: 100 ans. 42.8 



190 

This is practically 43 per cent. Therefore, 43 per cent, of the 
total width belongs to the tooth. 

The next part of the problem is the lifts. The total combined 
lifts of tooth and pallet equals 8l^ degrees. Changing 8i^ degrees 
to minutes gives 510 minutes. As 43 per cent, of the width be- 
longs to the tooth, then about 43 per cent, in the example we are 
figuring on belongs to the lift. Therefore 510. X 43. = 219.3 
minutes or 3° 39' represents the lift for the teeth. This Is usually 
modified to some extent. In this particular instance we shall 
deduct 11 per cent, from the lift on the tooth and add it to the 
lift on the pallet — ^viz., 11 per cent, of 219.3 minutes equals 24., 
therefore 219. — 24. = 195', or 3° 15', which is the lift we assign 
to the tooth. 

The total lift amounted to 8* 30', subtracting the tooth's 
lift, 3° 15' from this leaves 5° 15' as the lift on pallet. 

Here are the results tabulated: 

Width tooth, 41/2° 

Width pallet, 6° 

Lift tooth, 3^° 

Lift pallet, 51^° 

Calculations made with other escapement specifications will 
show various ways of dividing the width; and variations in the 
amount of the lift deducted from tooth and added to the pallet. 



191 



LESSON 124 



FACTS PRACTICAL AND THEORETICAL NO. 7 



422. Freedom of Tooth's Heel from Pallet Center — The below 
tables will be found useful for calculating the space existing 
between the heel of a tooth and the pallet center. 

Pallets of the circular or equidistant type have, or should 
have, the pallet staff planted at the meeting point of the tangents, 
unless the escapement is very small. Small escapements if 
planted on tangents, owing to the lift on tooth, lack room between 
the heels of the teeth and pallet center ; therefore but little space 
is left for the pallet staff. In larger escapements this difficulty is 
not experienced. 

Moduli for Freedom of Pallet Center from Point of Tooth — 

Lift tooth Moduli 

234° 110 

3° 108 

3%° 105 

31/2° 103 

334° 101 

4° 100 

Example — If the distance between the escape wheel and 
pallet centers measures 3.6 millimeters and the lift on tooth is 
3 degrees; calculate by means of the above table the space sep- 
arating the heel of tooth from pallet center: 

Rule — Multiply the distance of centers by the modulus 
associated with the lift on tooth. Therefore: 

3.6 X .108 = .38 

The answer, .38 millimeters, represents the space between 
heel of tooth and pallet center. This allows sufficient room for 
the pallet staff. 



192 



Alterations 



ALTERATIONS NO. 1 

423. Remarks — Scattered through this hook are suggestions 
on the alteration of parts. In this series on alterations we have 
assembled explanations which beginners will find useful. The 
"don'ts" connected with alterations are here omitted. 

424. Diamond Lavs — Students interested in escapement work 
will find a set of diamond laps of different degrees of fineness a 
valuable acquisition, and are advised to either make or purchase 
same. 

425. Pallet Stone Setters — For altering the lock on a pallet 
stone, use a tool so constructed that either stone can be heated 
independently of the other. A pallet stone setter of this class 
will save both time and trouble. 



LESSON 125 

ALTERATIONS NO. 2 

426. Grinding a Pallet Stone Thinner. — Method A — Cement 
pallet jewel to the flattened end of a brass wire. The part of the 
stone to grind off is its back. The pallet jewel therefore should 
be cemented on the end of the wire with its back uppermost. 

Place a diamond lap in the lathe. Revolve it at a moderate 
speed. Hold the pallet stone against the lap. Use a little oil to 
assist the grinding. A few minutes will complete the operation. 

Method B — A wedged-shaped slice from the back of a pallet 
jewel near the releasing corner can be ground away, without the 
necessity of removing the pallet stone from its seat in the pallet 
arm. Methods A and B will prove useful for increasing the 
amount of drop or shake in lower grade watches. 

LESSON 126 

ALTERATIONS NO. 3 

427. Changing Angle of Lift on Pallet Jewel. — When the lift- 
ing or impulse face of a pallet stone and the lifting face of a 
tooth show irregularities in the action of their lifts, we must, 
to correct the mismatched lifting action make some of the follow- 
ing alterations. 



193 

Method A — Supply a new pallet stone with a lifting face 
matching the lift on tooth. 

Method B — Change the slant of the pallet stone in its seat so 
as to obtain a different lifting effect. This alters the relation of 
the pallet's impulse face with tooth's. 

Method C — Sometimes to alter the slant of a pallet stone it is 
necessary to cut, by filing the sides of the seat in the pallet arms 
which retain the pallet jewel. This sometimes allows us to so 
pitch the stone that the matching is much improved. 

Method D — To grind and polish to a different angle a pallet 
jewel's lifting face is a feat beyond the average horological 
mechanic. Hence there is no advantage in further discussing 
same. 

LESSON 127 

ALTERATIONS NO. 4 A 

428. Increasing a Lever's Entire Length. — Method A — Supply 
a new and longer lever. 

Method B — If the lever is soft it can be stretched by tapping 
with a hammer that part of the lever between the pallet staff 
and guard pin. 

ALTERATIONS NO. 4 B 

429. Increasing a Lever's Acting Length. — Method A — Supply 
a new lever. 

Method B — Stretch the side walls of the slot by hammering, 
after which carefully redress and refinish the fork. 

Method G — Advance the position of the roller jewel or supply 
a new table, one holding the roller more forward. Method C is 
an indirect way of correcting errors attributable to a short lever. 

ALTERATIONS NO. 4C 

430. Decreasing a Lever's Acting Length. — Method A — Fur- 
nish a new lever. 

Method B — File or grind away the horns, then refinish and 
polish them. 

Method C — Errors caused by a long lever can at times be 
overcome by setting the roller jewel further back — that is, to- 
ward center of table. 



LESSON 128 



ALTERATIONS NO. 5 A 
431. Advancing the Position of the Guard Point. — The inten- 
tion of advancing the position of a guard point is to lessen the 



194 

freedom between guard point and table — viz., to decrease the 
guard freedom. 

Method A — Supply a new table greater in diameter. 

Method B — Remove old guard pin broach out of hole and in- 
sert a thicker pin. 

Method G — Continue use of old pin, but make it "question 
mark" in shape. 

Method D — If the guard point of a double roller escapement 
is short it can be made longer by squeezing with a pair of flat- 
nosed plyers, whose jaws inside are highly polished. 

ALTERATION NO. 5B 

432. When the Guard Point is Too Close. — Should tests 
develop the fact that a guard point is too close to edge of table, 
their distance can be increased by using some of the following 
methods: 

Method A — Select a new table lesser in diameter. 

Method B — Place old table in the lathe. (Not infrequently 
it can be left on its staff. It is always advisable to remove the 
roller jewel.) Then, with either lap or graver, cut edge of table 
away. Of course a lap is preferable for this purpose. Afterward 
highly polish the table's edge. 

Method G — Replace old guard pin with one that tapers 
slightly. 

Method D — Use tool described in Lesson 134. Shave face and 
sides of the original guard pin. 

Method E — If the guard point in a double roller is too long, 
use a fine file to shorten it, then burnish. (Note — If guard finger 
is short, grasp it with plyers; a slight squeeze will stretch it the 
desired amount.) 

LESSON 129 

ALTERATIONS NO. 6 A 

433. When the Roller Jewel and Slot Gorners Are Too Close. — • 
Method A — Select a new table with roller jewel nearer center of 
table. 

Method B — Enlarge hole in old table and set roller jewel 
further back. 

Method G — Reduce the lever's acting length. 

ALTERATIONS NO. 6B 

434. When the Roller Jewel and Slot Gorners Are Too Far 
Apart. — Method A — Choose a new table, one holding the roller 
jewel more forward. 

Method B — Enlarge hole in old table in such a way that the 
roller jewel will occupy a more advanced position. 
Method G — Increase the lever's acting length. 



195 

LESSON 130 

ALTERATIONS NO. 7 A 

435. When the Tahle is Too Large.— Method A— Furnish a 
new table lesser in diameter. 

Method B— Secure the table to the lathe; turn or grind off 
some of the edge. When finished the edge of table should show 
a high polish. 

Method (7— Frequentiy the old table can be used without 
altering it. Under such circumstances the guard pin can be made 
thinner, or the guard finger shortened. 

ALTERATIONS NO. 7B 

436. When the Tahle Is Too Small. — Method A — Procure a 
larger table. 

Method B— If the small table is retained advance the guard 
pin, making same "question mark" in shape. In double roller 
escapements the guard finger can be stretched in the manner 
directed in Lesson 128. 

LESSON 131 

ALTERATIONS NO. 8 A 

437. Increasing Drop and Shake. — Method A — Employ thin- 
ner pallet jewels. 

Method B — Grind off the entire back of one or both pallet 
stones. 

Method C — Grind a V shaped slice off the back of pallet 
stone, the base of cut being the releasing corner. 

Method D — Spreading both pallet stones apart increases in- 
side drop and shake. 

Method E — Closing both pallet stone — i. e., bringing their 
respective releasing corners closer together increases outside drop 
and shake. 

Method F — Increasing the drop lock by pushing out the 
receiving pallet increases inside drop and shake. 

Method G — Increasing drop lock by pushing out the dis- 
charging pallet increases outside drop and shake. (The con- 
trary is true of P and G when the stones are pushed back.) 

Note — When either methods, D or E, are used, it is sometimes 
necessary to use a file to enlarge the slot containing each pallet 
stone. 

Note — Increasing drop lock by pushing out one pallet stone 
increases the extent of drop lock on opposite stone. This the 
student can demonstrate by actual experiment. 



196 
ALTERATIONS NO. 8B 

438. Lessening Drop and Shake. — Method A — Use thicker 
pallet stones. 

Method B — Spreading the stones apart decreases outside 
drop and shake. 

Method G — Closing the stones together — that is, bringing 
their ends closer together — decreases inside drop and shake. 

Method D — Increasing drop lock by pushing out the receiving 
pallet stone decreases outside drop and shake. 

Method E — Increasing drop lock by pushing out the dis- 
charging pallet jewel decreases inside drop and shake. 

Note — Lessening the drop lock on receiving pallet, by push- 
ing it back in its seat, decreases inside drop and shake. Com- 
pare with Method F, Paragraph 437. 

Lessening drop lock on discharging pallet, by pushing same 
back, decreases the outside shake. Compare with Method G, 
paragraph 437. 



LESSON 132 



ALTERATIONS NO. 9 

439. Iinproving Draw. — Method A — As defective draw is 
sometimes due to unsuitable pallet stones, replace old with 
correct jewels. 

Method B — Change the slant of offending stone in the desired 
direction. Usually increasing the pitch of a stone increases the 
draw, and vice versa, decreasing the slant, lessens draw. Ex- 
tremes in pitch of stones must be avoided, as it destroys draw. 

Method G — When an escape wheel shows signs of abuse the 
draw will be found irregular; some teeth will show good draw, 
others will not. Such a wheel should be replaced by a new one. 



LESSON 133 



ALTERATIONS NO. 10 

440. Straightening or Bending Levers. — As a rule, thin levers, 
such as are found in 0-12 and 16 size watches, can be bent without 
any great risk of breakage. 

Bending Tool, Method A — An excellent tool for bending 
levers can be made from plyers having one nose convex, the other 
concave. A set screw being so placed in the handle that the 
amount of bending is under the control of the set screw. Several 
sizes of tools are necessary to meet the varying lengths of levers. 

Method B — Assuming the lever is in position in the watch 



197 

and as the workman looks at it the lever is at rest against the 
right-hand hank — first, take a fine screwdriver and, with the 
left hand, hold it against the left side of the lever. The point 
of the tool being back as far as possible, and placed under the 
bridge if it can be managed; second, take another but larger 
screwdriver, place it against the right side of the lever and with 
it bear against side of lever. In this way the lever can readily be 
bent. A few experiments will soon teach the operation. 



LESSON 134 



ALTERATIONS NO. 11 
441. Tool for Thinning Guard Pins. — Select a needle or piece 
of steel wire the thickness of a fine darning needle. Drill a hole 
in one end, using a drill the size of a guard pin. The wire still 
being in the lathe, turn drilled end tapering. Then with an oil- 
stone slip sharpen the end. Next with a file flatten off one side, 
cutting away about one-third of the wire in order to reach the 
hole. Cutting into the hole drilled in the tool is done for clear- 
ance, so that when the tool is used — namely, slipped over the 
guard pin— brass shaving cannot become clogged inside. When 
finished the cutter should be tempered. A set of three having 
various sized holes to fit different thickness of guard pins will 
be found useful not only for thinning guard pins, but for remov- 
ing the belly left on a guard pin when it is slightly inclined 
away from edge of table. 



LESSON 135 



ALTERATIONS NO. 12 
442. Guard Pins Shaped "Question Mark.'' — When necessary 
to bring the guard pin more forward, it is best to shape it into a 
question-mark pin, such as is found in Waltham watches. This 
is an excellent shape, because of the latitude it allows for adjust- 
ment. A suitable tool can readily be made or purchased for 
forming pins into this shape. 



198 

QUESTIONS FOR RESEARCH WORK 



The following list of questions, numl)ered consecutively from 
1 to JflS, has been compiled so that the important points involved 
in Escapement Knowledge may te brought before the student in 
detail. With each question is given the number of the paragraph 
in which an answer or explanation may be found. Research 
along these lines cannot fail to result in the student rapidly 
acquiring a thorough working knowledge of the problems relating 
to the subject upon which this work has been published. 

Draw 

443. Questions on Draw. — 

1 
Explain the term "draw." 23. 

2 
Why is the locking face of a pallet jewel given a slant? 110. 

3 
From what point does the draft angle of a pallet stone arise? 
114, 214. 

4 
What is the cause of draw? 147. 

5 
In what way does the lever show the presence of draw? 147. 

6 
Is slide the result of draw? 148. 

7 
If the draw is poor will slide aid? 148. 

8 
When draw is defective, will the lever rest securely against 
its bank? 148. 

9 
How would you examine the draw? 152, 153, 154, 155. 

10 
What force aims to prevent contact of guard point with edge 
of table? 149. 

11 
If "draw" is not strong enough to retain the lever against its 
bank, will it cause trouble, and why? 149. 

12 
Is there any connection between slide and draw? 148. 

13 
If an escapement is banked to drop, will draw be present? 
179. 



199 

14 
Name the three phases of escapement action in a double 
roller escapement where draw must be effective. 151. 

15 
Name the three phases of action in a single roller escape- 
ment where draw must be effective. 150. 

16 
In a double roller escapement, when the guard finger is 
brought into contact with the edge of the table, what force 
releases them? 162. 

17 
Should a watch receive a shock when the guard finger enters 
the crescent and the lever thereby be jolted away from its bank 
what causes the lever to return to its bank? 153. 

18 
Should the slot corner be thrown in contact with the roller 
jewel will the parts mentioned remain in contact if the draw Is 
sound? 154. 

19 
If a watch is clean and freshly oiled, and the draw is poor, 
how can the force of draw be increased? 156, 439. 

20 
When the guard pin is outside the crescent and the watch 
receives a violent shock sufficient to throw the lever off its bank, 
what parts are liable to come into contact? Also, will they remain 
in contact? 150. 

21 
Should the lever be thrown off its bank when the guard pin 
enters the crescent, name the parts which will come in contact, 
and state by what agency the parts are separated? 150. 

22 
When, from any cause, the slot corner and roller jewel are 
brought in touch with each other, name the force which returns 
the lever to its bank? 150. 

23 
By what means may the amount of draw be increased or 
decreased? 156, 439. 

24 
Suppose, to alter "draw" it becomes necessary to change the 
slant of a pallet stone, name the four points calling for investi- 
gation. 156. 



200 



Drop 

444. Questions on Drop. — 

25 
What is drop? 17, 157. 

26 
State source of angle of drop and give its usual size. 127. 

27 
From what center is the angle of drop measured? 182, 21S. 

28 
Into how many classes is drop divided? 128. 

29 
What is meant by "inside drop"? 18. 

30 
Define "outside drop." 19. 

31 
State whether the drops are more equal when steel escape 
wheels are used, and why. 159. 

32 
Explain the manner of testing inside drop. 163, 285. 

33 
How would you examine the outside drop? 161, 284. 

34 
Explain method whereby the extent of the angle of drop in 
an escapement can be approximated. 182, 184. 

35 
Which is least in amount, "drop" or "shake"? 158. 

36 
When, in order to correct an error of drop or of shake, we 
desire to alter but one pallet stone, how would you decide which 
stone to alter? 165, 437, 438. 

37 
When drop, or shake, is tight outside, how can it be cor- 
rected? 166, 437, 438. 

38 
If defective drop or shake is due to a thick pallet jewel, how 
would you remedy it? 167, 437. 

39 
Explain how you would correct drop or shake when tight 
inside. 165, 437, 438. 

40 
What is meant by the terms "outside" and "inside" as applied 
to the subjects of "drop" and "shake"? 18, 19, 20, 21. 

41 
If the amount of drop in an escapement equals one-half the 
width of the pallet jewel, and we assume the width of the pallet 
as 5 degrees, what size is the angle of drop? 182, 184. 



201 

Shake 

445. Questions on Shake. — 

42 
Define the term "shake." 20. 

43 
Explain what the term "inside shake" means. 21. 

44 
What is meant by "outside shake"? 22. 

45 
When the drops are unequal, how will it affect the shakes? 
130. 

46 
Can shake exist without drop? 130. 

47 
How many classes of shake are there? 130, 158. 

48 
How would you find out if shake is prseent? 21, 22. 

49 
Explain how you would test the "outside shake"? 162, 286. 

50 
State how the "inside shake" is tested? 164, 285. 

51 
Will want of shake cause a watch to stop? 130. 

52 
When irregularities in the shakes are discovered, what should 
be first examined? 165. 

53 
What important points require attention when shake is 
altered? 156. 

54 
When inside drop and inside shake is deficient, how would 
you provide same? 167, 437, 438. 

55 
Suppose we desire to change but one pallet stone to help 
correct an error of shake or drop, how would you decide which 
pallet stone to alter? 167, 437, 438. 

56 
When outside shake is wanting, how would you provide 
same? 168, 437, 438. 

57 
Given an escapement, in what way would you approximate 
the degrees of inside and outside shake? 184 A. 

58 
If the quantity of shake equals one-fifth the width of a pallet, 
state in degrees the approximate amount of shake present. 184 A. 



202 

The Lever 

446. Questions on the Lever. — 

59 
Define "lever." 47. 

60 
Define "horns of lever." 49. 

61 
Define "slot or notch." 50. 

62 
Define "fork." 51. 

63 
What parts of the lever comprise the fork? 135. 

64 
Where are the slot corners located? 135. 

65 
What is meant by the term "lever's acting length"? 48. 

66 
Explain what is meant hy "run of lever"? 52. 

67 
Is it necessary for the lever of a single roller escapement to 
have long horns? 136. 

68 
Are the horns in a single roller escapement factors in the 
safety action? 136. 

69 
What is the purpose of the slot? 137. 

70 
Name and locate the lifting or impulse planes which move 
the lever? 137. 

71 
State where the angles relating to the fork originate and 
describe them. 138. 

72 
In a double roller escapement, how would you find out if the 
length of horn is correct? 207. 

73 
What force retains the lever against its bank? 149. 

74 
Are the slot corners factors in the safety action? 187, 199. 

75 
Is the acting length of the lever related in any way to the 
amount of drop lock? 269, 270. 

76 
Given the drop locks as correct, how would you decide if 
the lever's acting length is correct? 250, 254, 257. 



203 



The Pallets 



77 
What parts constitute the pallets? 53. 

78 
Name that part of the pallets which holds' the pallet 
jewels? 54. 

79 
Define "entering or receiving pallet." 57. 

80 
Define "exit or discharging pallet." 58. 

81 
Make a sketch and mark out a pallet jewel's locking and 
impulse face. 59, 61, 110. 

82 
Define "releasing corner of pallet." 62. 

83 
Explain why the locking face of a pallet jewel is given a 
slant. 110. 

84 
Explain purpose of the impulse plane on a pallet stone. 110. 

85 
Name, and state sources of all angles, giving shape to a 
pallet jewel. Ill, 112, 113, 114. 

86 
Where does the angle of impulse which forms the lifting 
plane of a pallet arise? 112. 

87 
Name, and give origin of angle which controls the width of 
a pallet jewel. 113. 

88 
From what point does the draft angle of a pallet jewel arise? 
114. 

89 
Prom what center does the angle of lock originate? 212. 

90 
Has the angle of lock any connection with the shape of the 
pallet jewel? 115. 

91 
Mention the important points which require attention when 
the position of a pallet jewel is altered. 156. 

92 
When an escapement trips, upon what part of the surface 
of a pallet jewel will the toe of the escape wheel tooth be found? 
86, 192. 



204 

93 
In American watches, which type of pallet is used — viz., 
circular or equidistant? 116. 

94 
How woud you recognize pallets of the circular type? 116. 

95 
Are the locking faces of circular pallets at an equal distance 
from the pallet center? 116. 

96 
How are pallets of the equidistant type recognized? Also, 
state if there are any inequalities in the measure of the distance 
between each locking corner and the pallet center? 117. 

97 
Should the complete pallets of a foreign make of watch 
become lost, how would you estimate the dimensions of new 
pallets? 414. 



205 

Lift on Pallet 

448, Questions — Lift on Pallet. — 

98 
Locate the impulse face of a pallet jewel. 60, 110. 

99 
What is meant by "lift on pallet"? 60, 112. 

100 
Is the impulse plane related, to the lift? 110. 

101 
The ange of impulse of a pallet stone arises from what 
center? 112, 212. 

102 
When the lifting planes of tooth and pallet start action, 
which of the following would you say is correct: (a) The pallet 
corner to start action on the tooth's impulse face, or (b) the toe 
of the tooth to commence action on the impulse face of the pallet? 
170. 

103 
When the "lifts" are defective, what may be expected about 
the going of the watch? 170. 

104 
Explain how errors due to mismatched lifts can be lessened. 
171. 



206 

Tooth of Escape Wheel 

449. Questions — Tooth of Escape Wheel. — 

105 
Name the acting parts of a club tooth. 120. 

106 
What part of a club tooth should rest on the locking face of 
a pallet? 120. 

107 
Give location of tooth's impulse plane. 121. 

108 
Why is the line B. C, Pig. 9, of a tooth given a slant? 122. 

109 
Where does the lifting angle of a tooth originate? 124. 

110 
The degrees of width granted a tooth are measured from 
what center? 125. 

Ill 
From what point is the slant of a tooth's locking face meas- 
ured? 126. 

112 
The shape of a club tooth is controlled by what angles? 123. 

113 
What feature governs the undercutting A to N, Fig. 9, which 
helps shape a tooth? 120. 

114 
If a ratchet tooth escape wheel or a club tooth escape wheel 
are destroyed or unfindable, explain how you would find the size 
of a new wheel. 413. 



207 



Lift on Tooth 

450, Questions — Lift on Tooth. — 

115 
Explain the term "lift on tooth." 32. 

116 
Where is a tooth's impulse face located? 34, 121. 

117 
Locate the heel of a tooth. 35. 

118 
Locate the toe of a tooth. 36. 

119 
Why does a club tooth possess an impulse plane? 121. 

120 
Describe the correct relation of a tooth's lifting plane when 
acting upon the lifting plane of a pallet jewel. 169. 

121 
Where does the lifting angle of a tooth arise? 124. 



208 



Drop Lock 



451. Questions on Drop Lock. — 

122 
From what center does the angle of lock arise? 212. 

122 A 
Define and explain the term "drop lock." 38, 173. 

123 
What controls the amount of drop lock? 173. 

124 
Is drop lock a product of the banking pins? 173. 

125 
As regards the drop lock, what is meant when we say an 
escapement is "banked to drop"? 173. 

126 
Is the amount of drop lock associated in any way with the 
safe action of an escapement? 217. 

127 
Take a movement and estimate the amount of its drop lock. 
183. 

128 
How can the degrees of drop lock be measured? 417. 

129 
What does the expression "correct drop lock" mean? 268, 
269, 270. 

130 
Would the extent of drop lock exactly suited to a high 
grade watch be equally well adapted to a low grade watch? 265. 

131 
On the basis of drop lock, name the three divisions into 
which for practical reasons escapements may be separated. 266. 

132 
What is meant by "a perfect escapement"? 268. 

133 
What does the term "correct escapement" imply? 269. 

134 
Explain what is meant by the expression "commercially 
correct escapement." 270. 

135 
Has the amount of drop lock any relationship to the lever's 
acting length? 250. 

136 
Which should be greatest, guard freedom or drop lock? 322. 

137 
In an Elgin type of escapement, which should be least, 
corner freedom or drop lock? 322 



209 

138 
Does the extent of drop lock in an Elgin type of escapement 
differ from that found in an escapement of the South Bend type? 
275, 276. 

138, Section 1 
If the receiving stone is pushed out, thereby making its drop 
lock greater, how will it affect the following: (a) Drop lock on 
discharging pallet, (b) inside drop, (c) inside shake? 308 (note). 
138, Section 2 
When the discharging stone is pushed out, thereby making 
its drop lock greater, how are the following affected: (a) Drop 
lock on receiving stone, (b) outside drop, (c) outside shake? 
308 (note). 

138, Section 3 
Suppose we lessen the drop lock on the receiving stone by 
pushing this stone back into its seat, what effect will this have 
on the following: (a) Drop lock on discharging pallet, (b) inside 
drop, (c) inside shake? 309. 

138, Section 4 
By pushing the discharging stone back its drop lock is de- 
creased; mention the effect this will have on the following: 
(a) Drop lock on receiving pallet, (b) outside drop, (c) outside 
shake. 309. 



210 

Slide 

452. Questions on Slide. — 

139 
Define "slide." 41. 

140 
What is meant by slide or slide lock? 148, 174. 

141 
What controls the amount of slide? 148, 174. 

142 
Does any relationship exist between "slide" and "draw"? 
148. 

143 
If an escapement is banked to drop, would slide be present? 
174. 

144 
Is the run of the lever related to slide? 52. 

145 
What is meant by "banked for slide"? 16. 

146 
How can the slide lock be increased? 174. 

147 
Is the amount of guard freedom and amount of corner free- 
dom related to slide, and in what way? 244 to 248. 



Total Lock 



453. Questions on Total Lock. — 

148 
Define "total lock." 45. 

149 
Of what is the total lock composed? 172. 

150 
Given an escapement, how would you approximate the degrees 
of total lock? 183. 

151 
How can the degrees of total lock be measured? 417. 



211 

Safety Lock 

454. Questions on the Safety Lock. — 

152 
Define "safety lock." 44. 

153 
Explain the purpose of a safety or remaining lock. 176. 

154 
Name the three safety locks. 402. 

155 
When tests show an absence of safety lock, what error de- 
velops? 176. 

156 
How would you demonstrate the presence of a guard safety 
lock, a corner safety lock, a curve safety lock? 193, 194, 195, 204, 
205, 206. 

Bank and Banking Pins 

455. Questions — Bank and Banking Pins. — 

157 
Explain the term "bank." 12. 

158 
Define "banking pin." 11. 

159 
Describe the banking pins and their purpose. 178. 

160 
What is expressed by the term "banking error." 10. 

Overbanking 

456. Questions on Overltanking . — 

161 
Define "overbanked." 46. 

162 
What is meant when we say "an escapement is overbanked"? 
191. 

163 
Name some causes of overbanking. 191. 



212 



Banked to Drop 

457. Questions — Banked to Drop. — 



164 
What does the term "banked to drop" imply? 13. 

165 
Describe the best method for unlocking escapement errors. 
179. 

166 
What is meant when we say "a watch is banked to drop"? 
179. 

167 
Explain the method of banking an escapement to drop. 223. 

168 
When an escapement is banked to drop will slide be present? 
179. 

169 
Is draw present when an escapement is banked to drop? 179. 

170 
When a watch of the Elgin type is banked to drop, will 
freedom be found between the guard point and the table? 14, 
179, 288. 

171 
If an Elgin type of escapement is banked to drop, will 
corner freedom be present? 14, 293. 

172 
Is it correct or incorrect to find guard freedom present when 
a Dueber or South Bend escapement is banked to drop? 15, 291. 

173 
When a watch of the South Bend type is banked to drop, will 
corner freedom be present? 15, 296. 

174 
When banked to drop and escapement parts are well matched, 
state the proof-findings of the following guard, corner and angular 
tests, the watch being of the Elgin type? 15, 291. 

175 
In a South Bend type of escapement, when the parts are 
well matched and watch is banked to drop, what are the proof 
test findings of the guard, corner and angular tests? 



213 



Impulse and Safety Tables 

458. Questions — Impulse and Safety Tables. — 

176 
Describe the roller table found in single roller escapements. 
76, 144. 

177 
Describe a safety roller. 74. 

178 
What is meant by diameter of table? 76. 

179 
What is the necessity for a crescent or passing hollow? 
75, 146. 

180 
In a double roller escapement, what table is associated with 
the safety action? 144. 

181 
When the guard point is thrown in contact with the edge of 
tke table, what force causes the parts to separate? 150, 151. 

182 
From what center does the angle originate, which provides 
freedom between edge of table and guard pin? 211. 

183 
Under "banked to drop" conditions, will the guard point 
touch the edge of a table (a) in an Elgin, (b) in a Dueber? 14, 
15, 226. 228. 



214 



Roller Jewel 



459. Questions — Roller Jewel. — 

184 
By what other names is the roller jewel known? 65. 

185 
Why is the face of a roller jewel flattened? 141. 

186 
What is meant by "roller jewel radius"? 66. 

187 
Define "impulse radius." 143. 
188 
From what center is the width of a roller jewel measured? 
143. 

189 
Explain how you would find out if the roller jewel fits the 
lever slot. 287. 

190 
Describe how a roller jewel should be reset so that its position 
matches the escapement action (a) in an Elgin, (b) in a South 
Bend escapement. 267, 271, 272. 

191 
Describe the various positions and actions of a roller jewel 
when a watch is running. 142. 

192 
Elgin, B to D — where does the angle arise which provides 
freedom between the roller jewel and slot corner? 143. 

193 
Does slide increase the corner freedom? 143. 

194 
If an escapement of the Elgin type is banked to drop, would 
you expect to find freedom between the slot corner and roller 
jewel? 14, 240. 

195 
Name the escapement type, which, when banked to drop, 
allows no freedom between slot corners and roller jewel. 240. 

196 
When by accident the slot corner is thrown into contact with 
the face of the roller jewel, slide being present, what force pulls 
them apart? 148. 

197 
The roller jewel as a part factor in the safety action is asso- 
ciated with what parts? 187, 199. 



215 

198 
In a single roller escapement, what are the functions of the 
roller jewel as a factor in the safety action? 189. 

199 
In a double roller escapement, when the lever horn is thrown 
in contact with the roller jewel, what causes the release of the 
parts? 148. 

200 
Describe the work of the roller jewel as a factor in the safety 
action of a double roller escapement. 201. 

201 
Explain relation of the lever horns to the roller jewel in 
single roller escapements. 196, 207, 298, 300. 

202 
Explain the curve test and its purpose. 197, 208. 



216 



Guard Point 



460. Questions on the Guard Point. — 

203 
Locate the guard pin and guard finger. 68, 69. 

204 
What is meant hy "guard radius"? 71. 

205 
Name source of angle which provides freedom between guard 
point and table. 145. 

206 
When the lever is at rest against its bank, slide being preseijit, 
what force guards against contact of guard point with table? 
147. 

207 
State three important positions of the guard pin during the 
routine action of an escapement. 186. 

208 
The escapement being in action, when is the guard pin closest 
to the edge of the table? 186. 

209 
When is the guard pin at its greatest distance from edge of 
table? 186. 

210 
As a factor in the safety action, name the parts with which 
the guard pin is associated. 187. 

211 
Name the functions of the guard finger as it relates to the 
safety action. 188. 

212 
In a single roller escapement, when the guard pin just enters 
the crescent, in what position is the roller jewel? 185. 

213 
In a double roller escapement, when the guard finger enters 
the crescent, state what part of the fork the roller jewel is then 
opposite? 198. 

214 
Describe the functions of the guard finger in a double roller 
escapement. 188. 

215 
While the guard finger of a double roller escapement remains 
within the crescent, how is the safety action preserved? 201. 

2iG 
When the guard point is held in contact with the edge of the 
table, what should the effect be as regards the lock? 204. 



217 



Safety Actions, S. R. 

461. Questions on the Safety Actions, Single Roller Escape- 
ment. — 

217 
What is the purpose of the safety actions? 187. 

218 
In single roller escapements, name the parts which insure 
the safe action of an escapement. 67, 187. 

219 
Describe the office of the guard pin as a factor in the safety 
action. 188, 200. 

L20 
The roller jewel as a factor in the safety action is associated 
with what parts? 189. 

221 
What is meant by "overbanking"? 190. 

»/ V *> 

What causes overbanking? 191. 

223 
Explain the term "remaining lock." 44. 

2f4 
Should a watch receive a jolt when the crescent is well past 
the guard pin, explain how the safe action of the escapement is 
preserved. 190. 

225 
In the event of the lever leaving its bank during the time the 
guard pin is within the crescent, what parts are then called upon 
to preserve the escapement from going out of action? 184. 

What insures the escapement remaining in action, should 
the lever be thrown away from its bank when the roller jewel Is 
opposite the slot corner? 201. 

r/27 

When the roller jewel is opposite that part of the lever horn, 
near the slot corner, what preserves the safety action of the 
escapement should the lever be thrown off its bank? 188, 196, 
197. 



218 

Safety Actions, D. R. 

462. Questions on the Safety Actions — Double Roller. — 

228 
Name the safety action parts of a double roller escapement. 
199. 

2?9 
What is the preventative function of the guard finger? 200. 

£S0 
Name the functions of the roller jewel as a part of the safety 
action. 201. 

231 
How would you decide if the length of horns are correct? 
207. 

232 
While the guard finger remains outside the crescent, what 
parts when called upon insure the escapement remaining in 
action? 201. 

233 
As a part of the safety action, with what is the guard finger 
associated? 199. 

284 
The lever horn is associated with what part as a preserver of 
the safety action? 201. 

235 
Name the chief parts which act as a preventative of over- 
banking. 200. 

236 
State with what parts the roller jewel is associated to insure 
the safe action of an escapement. 201. 

237 
When the guard finger is within the crescent, upon what 
parts does the protection of the escapement's action depend? 201. 

237 A 
Is there any relationship between width of crescent and 
length of the horn? 198 (note), 207. 



219 



Tripping 



238 
463. Questions on Tripping — Single Roller. — 
Explain what is meant when we say "an escapement trips." 
192. 

239 
Define the following: "Guard trip," "corner trip," "curve 
trip." 87, 88, 89. 

240 
In how many positions can a trip occur? 192. 

241 
Explain the use of the guard safety test. 193. 

242 
Can an escapement trip on some teeth while other teeth 
possess a safety lock? 193. 

243 
Is the amount of guard freedom related to the locks? 224, 
289. 

243 A 
State causes for (a) guard trip, (b) a corner trip, when all 
escapement pivots fit their respective holes. 193, 194. 

244 
Describe use of corner safety test and explain its purpose. 
194. 

245 
How would you make use of the curve safety test and why? 
195. 

246 
If tripping errors are not corrected, what will the result be? 
192. 

247 
Has the amount of corner freedom any relation to the amount 
of drop lock? 225. 

464-465. Questions on Tripping — DouMe Roller. — 

248 
Name the three positions wherein to suspect the presence of 
tripping errors. 203. 

249 
How would you make use of the guard safety test? and tell 
why. 204. 

250 
How, and for what purpose is the curve safety test used? 
206. 

251 
The amount of lock and the amounts of guard and corner 
freedoms are related in both single and double roller escapements. 
State why the locks and freedoms are related. 225, 294. 



220 



Angular Test 

466. Questions on the Angular Test. — 

252 
Describe the system best adapted by beginners for applying 
the angular test. 258. 

253 
Why is it advisable for beginners to remove the guard point 
from edge of table when using the angular test? 259. 

254 
Explain method of blocking the lever when making use of 
the angular test. 258. 

255 
When the lever is blocked, at what moment should we cease 
rotating the balance? 258. 

256 
If the locks are correct, and the lever's acting length is 
adapted to the locks, when the angular test is used, state what 
position each tooth will occupy on each pallet (Elgin). 258. 

257 
What do the "proof findings" of the angular test imply? 190. 

258 
Describe a variation from the angular test's proof findings. 
258. 

259 
"Out of Angle" is shown in what manner by the angular 
test? 262. 

260 
What is the usual cause of an escapement being "out of 
angle"? 263. 

261 
Describe the angular test's proof findings for an escapement 
of the "South Bend type." 257. 

262 
In what way does the proof findings of an Elgin type of es- 
capement differ from the proof-findings of a South Bend or 
Dueber escapement? 254, 257. 

263 
Granted that the drop locks in an escapement of the Elgin 
type are correct, how would you prove that the length of the lever 
Is right? 258. 



221 



SUMMARY OF TESTS 
The Summary Includes 468 to 473 

467. Questions on Summary of Tests. — 

264 
Describe method for testing "draw." 281. 

265 
How would you test drop lock? 282. 

266 
Explain how you would test "drop," inside and outside. 283, 
284. 

267 
Describe manner of testing the inside and outside shakes. 
285, 286. 

268 
How would you determine the freedom of the roller jewel 
when held by the slot walls? 287. 



222 



The Guard Test 



468. Questions on the Guard Test — Single and Double Boi- 
ler— 

269 
Explain the term "guard freedom." 84. 

270 
What is the nature and purpose of the guard test? 288. 

271 
When we bank to drop escapements of the Elgin and South 
Bend types, state in which type guard freedom would be present. 
288. 

272 
Describe methods of making the guard test in escapements 
of the Elgin and South Bend types. 290, 291. 

273 
Explain the three classifications into which guard freedom 
may be divided. 304. 

274 
When the guard test is applied to a South Bend escapement, 
same being banked to drop, can the lever be lifted off its bank? 
Also, under like conditions, can the lever in an escapement of 
the Elgin type be lifted away from its bank? 290, 291. 



22j3 



The Corner Test 



469. Questions on the Corner Test — Single and Douhle 
Roller. — 

275 
What is meant by the term "corner freedom"? 79. 

276 
Describe manner of testing the corner freedoms in escape- 
ments of the Elgin and South Bend types. 295, 296. 

277 
If a watch of the Elgin type is banked to drop, would you 
consider the escapement correct if corner freedom is not present? 
293. 

278 
If we bank to drop escapements of the Elgin and South 
Bend types, would their corner freedoms be identical? 293, 
295, 296. 

279 
Into how many types may corner freedom be divided? 303. 



^24 



The Guard Safety Test 

470. Questions on the Guard Safety Test — Single and Double 
Roller. — 

280 
What does the term "guard trip" imply? 

281 
For what purpose is the guard safety test employed? 289. 

282 
When using the guard safety test, is it necessary to bank 
the escapement drop? 289. 

283 
Describe routine of making the guard safety test. 292. 



The Corner Safety Test 

471. Questions on the Corner Safety Test — Single and Double 
Roller. — 

284 
What is meant by the expression "corner trip"? 87. 

285 
If the corner safety test showed that the safety lock is 
uncertain, or absent, would it require correction? 192, 194. 

286 
Describe manner of using the corner safety test. 297. 

287 
When the corner safety test is employed, is it essential that 
the escapement be banked to drop? 

288 
How would you determine the condition of the corner safety 
lock? 297. 



225 



Curve Test and Curve Safety Test, S. R. 

472. Questions on the Curve Test and Curve Safety Test — 
Single Roller. — 

289 
Describe how the curve test is made, and its purpose. 298. 

290 
Should the curve test show that the roller jewel catches on 
the lever horns, would you consider the action correct? 298. 

291 
When using the curve test, what controls the extent of the 
horn with which the roller jewel can come in contact? 298. 

292 
What is the "curve safety test" and how is it employed? 299. 



Curve Test and Curve Safety Test, D. R. 

473. Questions on the Curve Test and Curve Safety Test — 
Double Roller. — 

293 
473. Describe method of using the curve test. 300. 

294 
When the curve test is used, state at what moment you 
would expect the roller jewel to come in contact with the horns 
of the lever. 300. 

295 
What is meant by "curve trip"? 88. 

296 
State the manor In which you apply the curve safety test, 
301. 



226 

Tests and Escapement Testing 

474. Questions on the Tests and Escapement Testing. — 

297 
Before testing an escapement, what points require atten- 
tion? 278. 

298 
Describe the routine of an escapement examination. 279. 

299 
If we desire to learn the relation of a guard point with its 
table, what tests are used? 290, 291. 

300 
When we wish to investigate the relation of the roller jewel 
with the slot corners, what test is employed? 295, 296. 

301 
What test informs us about the relation of the roller jewel 
to the curves of the horns? 298. 

302 
To investigate the condition of the safety actions in single 
and double roller escapements, name the tests employed? 293, 
297, 301. 

303 
What test informs us if the extent of drop lock present In any 
escapement is exactly adapted to the acting length of the lever? 
260. 



227 



Escapement Types 

475. Questions — Escapement Types. — 



304 
475. How many types of escapement are used in American 
watches? 274. 

305 
Of the total lock in an escapement of the Elgin type, how 
much belongs to the drop lock and how much is slide? 275. 

306 
In South Bend escapements, how much of the total lock is 
slide and how much is drop lock? 276. 

306 A 
Suppose you desired to examine the condition of an escape- 
ment in a foreign built watch, which type of American escape- 
ment will nearest apply? 276 (note). 



228 

Rules and Alterations 

476. Questions on Rules and Alterations. — 

307 
When the drop locks are increased — that is, made deeper—- 
what effect will changing the locks have on the following: (a) 
The bankings, (b) the guard freedoms, (c) the corner freedoms, 
(d) the safety locks? Alteration, 308, A, B, C, D. 

308 
If we make the drop locks lighter, describe effects produced 
on (a) the bankings, (b) the guard freedoms, (c) the corner 
freedoms, (d) the safety locks. Alteration, 309, A, B, C, D. 

309 
Describe how the corner freedoms may be increased. Altera- 
tions Nos. 1 and 2, 310. 

310 
Explain what alterations will decrease corner freedoms. 
Alterations Nos. 1 and 2, 311. 

311 
Name the changes whereby guard freedom can be increased. 
Alterations 1 and 2, 312. 

312 
Describe alterations which will decrease guard freedoms. 
Alterations 1 and 2, 313. 

313 
Given two escapements, both of them alike and identical, to 
which the following alterations are made: (a) In one we decrease 
the lever's acting length, (b) in the other we increase the drop 
locks; (c) state, if after alterations, their corner freedoms are 
similarly affected; (d) how do their respective corner safety 
locks show the change? 310. 

314 
If in this instance we are given two escapements, both of 
them correct and alike in their details, (a) when we increase the 
lever's acting length in one; and (b) decrease the drop locks in 
the other, will (c) the alterations cause resemblance in their 
respective corner freedoms, (d) in what way will the corner 
safety locks of each reflect the alterations? 311. 

315 
Assuming we have two escapements exactly alike and correct, 
(a) one of these we alter by bending the guard pin away from 
edge of table, (b) the other escapement we change by making 
the drop locks deeper, (c) state how the guard freedoms in each 
resemble each other, (d) In what way will the alteration in each 
escapement affect the guard safety locks? 312. 

316 
Again, assuming we have two escapements alike correct and 
duplicates, (a) the first we alter by bending the guard pin closer 



229 

to edge of table, (b) the second we change by decreasing the 
drop locks, (c) will their respective guard freedoms show any 
similarity? (d) Also, describe how the guard safety locks reflect 
the changes. 313. 

317 
When the position of the roller jewel is advanced, or the 
lever's acting length is m?«de shorter, state results as regards the 
corner freedoms and corner safety locks. 314. 

318 
When the lever is cut, thereby making the lever's acting 
length shorter, what is the effect on (a) the corner rreedoms, 
(b) the corner safety locks? 315. 

319 
When the bankings are spread apart, how will it affect the 
following: (a) The guard freedoms, (b) the corner freedoms, (c) 
the slide, (d) run of lever? 316. 

320 
State how the following are affected when the bankings are 
brought closer together: (a) The guard freedoms, (b) the corner 
freedoms, (c) the slide, (d) run of lever. 317. 

321 
When an Elgin type of escapement is banked to drop, will 
we find (a) any guard freedom, (b) any corner freedom? 318. 

322 
When an Elgin type of escapement is banked to drop, will 
the safety lock be equal or less than the drop lock? 318. 

323 
When banked to drop, will a South Bend type of escape- 
ment show any corner or guard freedom? 318. 

324 
Will the drop lock in a South Bend escapement equal or be 
less than the drop lock? 318. 

325 
What alterations must be made to correct a butting error? 
319. 

326 
State what protects the safety lock. 322. 

327 
If an escapement is " out of angle," how will such a condi- 
tion be expressed by the angular, corner, and guard tests? 323. 



230 



The Corner Test 



477. Questions on the Corner Test. — 

Note — When the abbreviations B. to D. are found opposite a 
question it indicates that the question expresses the condition 
of the escapement when banked to drop. 

328 

Elgin, B. to D. — Describe the proof findings of the corner test. 
325. 

329 

Elgin, B. to D. — In this watch, which is of low grade, the drop 
locks are unsafely light, but the corner freedoms are approxi- 
mately correct. The question is, when the drop locks are in- 
creased, in what way will it alter the corner freedoms, and what 
other changes might be required? 326. 

330 

Elgin, B. to D. — In this escapement the corner freedoms are 
seemingly right, but the drop locks are both deep. The problem 
is, if the drop locks are made correct — that is, lighter — how will 
this alteration act on the corner freedom, and what additional 
changes may be looked for? 327. 

331 

Elgin, B. to D. — In this instance the drop locks are correct, 
but the corner freedoms are too great. What changes are neces- 
sary to overcome the surplus corner freedoms? 328. 

332 

Elgin, B. to D, — When the drop locks are rather light and 
there is too much corner freedom, state how the corner freedoms 
will be affected, when the drop locks are made deeper, and what 
other alterations will be required to improve the escapement? 
329. 

333 

Elgin, B. to D. — In this escapement we find the drop locks 
ai'c deep, on testing the corner freedoms we find them excessive. 
What is the remedy? 330. 

334 

Elgin, B. to D. — The drop locks are correct, but by the corner 
test we find an absence of the corner freedoms. How can we over- 
come the defect? Also, state results. 331. 

335 

Elgin, B. to D. — When the drop locks are light and the roller 
jewel is unable to emerge from the slot, what alterations are 
necessary? 332. 



2ai 

336 
Elgin, B. to D. — Assuming an escapement with the following 
troubles, how would you rectify the errors: Drop locks deep, 
roller jewel unable to make its exit out of the slot? 333. 

337 
Elgin, B, to D. — When there is an absence of the corner free- 
doms, and the drop locks are correct, what alterations would be 
called for? 334. 

338 
Elgin, B. to D. — ^We find that the drop locks are rather light 
and the roller jewel is unable to leave the slot. What changes are 
necessary in this escapement? Also, name the order in which 
alterations should be made? 335. 

339 
Elgin, B. to D. — The defects in this escapement are deep 
drop locks and an absence of all corner freedoms. Explain how 
you would proceed to improve the escapement? 336. 



232 



Corner Safety Test 

478. Questions on the Corner Safety Test. — 



340 

Elgin, B. to D. — Given the drop locks as correct and the 
corner freedoms as likewise correct, but an examination shows 
that some teeth of the escape wheel will trip while others show 
a safety lock. Explain the cause of the tripping error and how 
a correction can be made? 337. 

341 

Elgin, B. to D. — ^An examination of this watch shows the 
drop locks as correct, but the corner freedoms are altogether too 
great. State what error will be found, and describe the altera- 
tions which will improve the escapement. 338. 

342 

Elgin, B. to D. — This escapement possesses the correct 
amount of corner freedoms, but the drop locks are decidedly too 
light, suflSciently so to cause tripping errors. How would you 
overcome the trip and what other changes might it be necessary 
to make? 339. 

343 

Elgin, B. to D. — Given the drop locks as deep, and the corher 
freedoms so excessive, they allow tripping to take place. In what 
order and way should alterations be made to restore the escape- 
ment to a more perfect condition? 340. 



233 



The Guard Test 

479. Questions on the Guard Test, — 

344 
Elgin, B. to D. — Describe the proof findings of tlie guard 
test. 325. 

345 
Elgin, B. to D. — If the guard freedoms are right, but the 
drop locks are too light, what will be the effect on the escapement 
if the locks are increased? 341. 

346 
Elgin, B. to D. — When the drop locks are deep and the guard 
test shows the guard freedoms as practically correct, mention 
the changes involved after correcting the error in the locks? 
342. 

347 
Elgin, B. to D. — This escapement's condition is as follows: 
Guard freedoms are slightly excessive, drop locks correct. State 
how would you alter the error in the guard freedoms. 343. 

348 
Elgin, B. to D. — The guard freedoms in this escapement are 
excessive, the drop locks are very light. What is the first altera- 
tion, and how does it affect the banking pins and the guard free- 
doms? Mention what other change is demanded. 344. 

349 
Elgin, B. to D. — Assuming an escapement with deep drop 
locks and a surplus amount of guard freedoms, state the required 
corrections. 345. 

350 
Elgin, B. to D. — In this escapement the drop locks are correct, 
but the guard test shows no freedom between the guard point 
and the table. What changes are implied? 346. 

351 
Elgin, B. to D. — When we discover an escapement wherein 
the drop locks are undoubtedly light, with no freedom between 
guard point and table, what is the first alteration? Also, state 
the additional changes which might be necessary. 347. 

352 
Elgin, B. to D. — Given the drop locks as deep and a condition 
of contact between guard point and table, what correction should 
be made at the start? And explain the nature of the alterations 
which follow? 348. 



234 

353 
When the guard point butts or sticks against the edge of the 
table and no legitimate manipulation of the guard point will 
overcome the defect, how can the butting error be remedied? 
349. 

353 A 
If when setting a watch, you push the second hand backward, 
and the watch stops, explain cause of error and its correction. 
349. 



235 



The Guard Safety Test 

480. Questions on the Guard Safety Test. — 

354 
Elgin, B. to D. — If the drop locks are quite right, and the 
guard freedoms are satisfactory, but we find that some teeth of 
the escape wheel trip while the majority show a safety lock, 
describe cause of trouble and how the tripping error can be 
remedied. 350. 

355 
Elgin, B. to D. — When we discover an escapement wherein 
the drop locks are correct, but the guard test reveals too much 
guard freedom, the result being a tripping error, explain how 
the escapement may be improved. 351. 

356 
If a trip is discovered under the following circumstances, 
drop locks light, guard freedoms correct, in what manner would 
you overcome the tendency to trip? 352. 

357 
In this instance the drop locks are light and the guard free- 
doms excessive. What error would be present and what correc- 
tions must be made? 353. 

358 
What correction will be necessary when the drop locks are 
deep and the guard freedoms excessive? 354. 



236 



Angular Test and Out of Angle 

481. Questions on the Angular Test and out of Angle (see 
paragraph 459). — 

359 
481. Assuming that the lever's acting length is correct, but 
the drop locks are too light, in what way will the angular test 
express the error of light locks? 358 (No. 4), 356. 

360 
Given the drop locks as deep and the lever's acting length as 
correct, explain how the angular test will show the error in the 
locks. 359 (No. 5), 356. 

361 
When the drop locks are correct, but the lever's acting length 
is too long, in what way will the excess in length of lever affect 
the teeth and pallets as determined by the angular test? 360 
(No. 2), 356. 

362 
How will the angular test show the defect in the lever's 
acting length, v/hen the lever is short and the drop locks correct? 
361 (No. 3), 356. 

363 
What is meant by the term "out of angle"? 91. 

364 
When an escapement is out of angle, how will the defect be 
shown by the following: (1) The drop locks, (2) the relation of 
guard point with table (3) the relation of slot corners to roller 
jewel, (4) the relation of teeth and pallets as determined by the 
angular test? 363. 

365 
In this watch the lever is straight, but the drop locks we 
find are very unequal. Describe the necessary correction and 
how the defect in the locks is exposed by the angular, guard and 
corner tests. 364, 366, 368. 

366 
When we find the drop locks are unequal and besides the 
lever is bent, what is the first alteration, and what other changes 
are always necessary? 365, 367, 369. 



237 



Curve and Curve Safety Tests 

482. Questions on the Curve and Curve Safety Test — Double 
Roller (see paragraph 4^6). — 

367 

482. What is meant by curve test and curve safety test? 
81, 82. 

368 
Should it be possible for the roller jewel to touch the end of 
the horn, how would you verify that contact of these parts is 
possible? 371. 

369 
How would you determine if the central part of the horn can 
seriously catch and hold the roller jewel? 372. 

370 
Explain method whereby you could find out if the roller jewel 
can stick, or catch on or near the slot corners. 373. 

371 
Describe the method of using, and nature of the curve safety 
test. 374. 

483. Questions on the Curve Safety Test — Single Roller (see 
paragraph 4^5). — 

372 
How would you prove that the roller jewel cannot touch 
the end or central part of the lever horn? 375. 

373 
State and describe the method, by means of which it can be 
learned if it is possible for the roller jewel to catch on either the 
slot corner, or that part of the horn near the slot corner. 376. 

374 
What is the curve safety test used for? And describe how 
It is used. 377. 



238 



Hints and Helps 

484. Questions on Hints and Helps. — 



375 
If the lock is considered "rather light," explain how it can 
be determined if such is a fact. 401. 

376 
Name the three positions where the safety locks require at- 
tention and examination? 402. 

377 
The bankings in this watch have been tampered with, besides 
both of the pallet jewels have been taken out of their settings. 
Describe the guard and corner test methods for correctly re- 
setting the pallet jewels and successful rematching of the escape- 
ment action? 403, 404, 405. 

378 
When one pallet is left in place, the opposite stone being 
removed from its seat, describe method used to secure a correct 
resetting of the loose pallet stone. 406. 

379 
Elgin, B. to D. — If you found contact of guard point with 
table, what changes and alterations can be made to improve 
the escapement and overcome the error? 407. 

380 
B. to D. — Should it be discovered that the guard point touches 
the edge of the table in some places, and is free in others, what 
would this indicate, and name remedies? 408. 

381 
B. to D. — How would you find out if the edge of the roller 
or safety table is running "true in the round"? 409. 

382 
Suppose you lost a roller table, state method of selecting a 
new one, right in diameter, and with the roller jewel correctly 
placed. 410. 

383 
The position the roller jewel occupies in a table is of great 
importance. If one is to be reset, state how it should be done to 
obtain correct rematching of its action. 411. 

384 
Describe the practical application of the corner test without 
having to bank the escapement to drop. 412, 



239 

385 
If you lost an English ratchet tooth escape wheel, how may 
the correct size of a new one be determined? 413. 

386 
When an escape wheel of the club tooth form is lost, how 
would you find the dimensions of a new one? 413. 

387 
Take any watch and prove that its escape wheel is correct 
in size. 413. 

388 
Given an escapement model, or a drawing, state how you 
verify if the size of the escape wheel is correct. 413. 

389 
Should pallets belonging to an equidistant type of escapement 
become destroyed or lost, describe how you would go to work to 
select new and suitable pallets. 414. 

390 
If pallets belonging to the circular class be mislaid or lost, 
and the watch is of foreign make, how would you attempt the 
selection of suitable sized pallets? 414. 



240 



Theory and Practice 

485. Questions on Theory and Practice. — 

391 
What is meant by "the angular motion of the lever"? 416. 

392 
What does the expression "roller jewel's impulse angle" im- 
ply? 416. 

393 
Explain how the lever's angular motion may he measured. 
417. 

394 
Describe how degrees of lock can be measured. 

395 
How would you measure the degrees of lift on a tooth of an 
escape wheel having club teeth? 417. 

396 
State how the lift on a pallet stone can be measured. 417. 

397 
How would you measure the size of the impulse angle? 417. 

398 
Explain the proportional method for calculating a lever's 
acting length and the radius of the roller jewel? 418. 

399 
Is there any difference between the practical and the theo- 
retical radius of the roller jewel? 419. 

400 
Given the degrees of lever's angular motion, and the impulse 
angle, how would you calculate the practical radius of the roller 
jev/el? 420. 

401 
When "the lifts" are divided, is there any relationship be- 
tween the amount of lift assigned to the tooth and amount given 
the pallet? 421. 

402 
Is it possible to plant all escapement on tangents? 422. 

403 
Give reason, why some pallets cannot be planted on tangents. 
422. 



241 



Altering Parts 

486. Questions on Altering Parts. — 



404 
Describe how a pallet stone may be ground thinner. 426. 

405 
How may the angle of lift on a pallet jewel be altered? 
427. 

406 
In what way can the entire length of a lever be increased? 
428. 

407 
Can the lever's acting length be increased, and how? 429. 

408 
How would you decrease the acting length of a lever? 430. 

409 
Explain the methods whereby the guard points' position 
could be advanced? 431. 

410 
When the guard point is "too close," state the remedies 
which may be used. 432. 

411 
When the roller jewel and slot corners are "too close," how 
should corrections be made? 433. 

412 
If the roller jewel and slot corners are too far apart, what 
alterations will overcome such a defect? 434. 

413 
Should the roller table be too large, describe changes which 
will correct the trouble? 435. 

414 
If a roller table is too small, what remedies would you sug- 
gest? 436. 

415 
Describe how "drop" or "shake" can be increased. 437. 

416 
If the "drop" or "shake" in an escapement is found to be too 
great, explain how same may be altered. 439. 

417 
Describe how "draw" may be improved. 439. 

418 
How would you lessen "draw"? 439. 



INDEX TO SUBJECTS 



A 

Acting Length of Lever 48 

Action of Escapement, Routine (D. R.) 198 

Action of Escapement, Routine (S. R.) 185 

Adjusting "Let Off" 92 

Advice and Remarks 306 

Altering Parts, Questions on 486 

American Escapement Types 274 

Angle of Draft, Pallet's 114 

Angle of Draft, Tooth's 126 

Angle of Drop 127 

Angle of Drop, Estimating the 182-184 

Angle of Freedom, The Roller's 145 

Angle of Impulse, Pallet's 112 

Angle of Impulse, Tooth's 124 

Angle of Lock 115 

Angle of Width, Pallet's 113 

Angle of Width, Tooth's 125 

Angle, Out of 91, 363 

Angle, Out of (Angular Test) 262, 323, 364 

Angle, Out of (Corner Test) 323, 368, 369 

Angle, Out of (Guard Test) 323, 366. 367 

Angle, Out of (Causes) 263 

Angles 94 

Angles Arising at Escape Wheel Center 213 

Angles Arising at Pallet Center 211 

Angles, Measurement of 105 

Angles of Fork 138 

Angles of Freedom 209 

Angles Radiating Towards Fork 211 

Angles Radiating Towards Pallet 212 

Angles Radiating Towards Tooth , 212 

Angles, Relationship of 209 

Angles Relating to the Roller Jewel 143 

Angles Shaping a Pallet Ill 

Angles Shaping a Tooth '. 123 

Angles, Source of Escapement 210, 214 

Angular Motion, Measuring Degrees of ". 417 

Angular Motion of the Lever 416 

Angular Test 77 



Angular Test, Blocking the Lever 260 

Angular Test, Errors as Shown by the 356 

Angular Test, Explanation of the (Elgin) 252 

Angular Test, Explanation of the (South Bend) 355 

Angular Test» How to Apply the , 258 

Angular Test, Index to Test Lessons on the 355 

Angular Test, Out of Angle as Shown by the 262, 364, 365 

Angular Test, Proof Findings of the 357 

Angular Test, Questions on the 466, 481 

Angular Test, Specifications 251 

Angular Test, Summary (Elgin) 254 

Angular Test, Summary (South Bend) 257 

Angular Test, Theoretical Explanation of the (Elgin) 253 

Angular Test, Theoretical Explanation of the (South Bend). 256 

Angular Test, The Guard Point and the 259 

Angular Test, Uses of the 250 

Angular Test, Variations from Proof Findings of the 261 

Approximating Degrees of Drop 184 

Approximating Degrees of Lock 181, 183 

Approximating Degrees of Shake 184 A 

Arc 97 

Arc of Vibration 108 

Arc, Supplementary 107 

B 

Balance 3 

Balance Arc 106 

Balance Arc of Vibration 108 

Balance Arc, Supplementary 107 

Balance, Motion of 109 

Balance Spring 8 

Balance Staff 7 

Balance Wheel 9 

Bank 12 

Banked for Slide 16 

Banked to Drop 13, 179 

Banked to Drop (Elgin) (Rule) 14, 318 

Banked to Drop (South Bend) (Rule) 15, 318 

Banked to Drop, Analysis of 224, 227 

Banked to Drop, Analysis of Corner Freedom 225, 240 

Banked to Drop, Analysis of Guard Freedom 224, 232 

Banked to Drop, Corner Test 240, 272, 273 

Banked to Drop, Guard Test 224, 272, 273 

Banked to Drop in Practice 271 

Banked to Drop, Its Relation to Drop Lock 223 

Banked to Drop Rules 318 

Banked to Drop Summary (Elgin) 226 

Banked to Drop Summary (South Bend) 228 



iii 

Banked to Drop, Test Findings 318 

Banked to Drop, Test Findings, Parts Matched (Elgin) 272 

Banked to Drop, Test Findings, Parts Matched (South Bend) 273 

Banking 10 

Banking Pins, Opening the (Rule) 316 

Banking Pins, Closing the (Rule) 317 

Bench Problems 386-399 

Butting Error (Rule) 319 

Butting Error, Test Lesson on 349 



Circles 95 

Circles, Rules Applying to 101 

Circles, Tables and Signs of 103 

Circular Pallets 63, 116 

Circular Pallets, Drafting 118 

Circular Pallets, Specifications for 119 

Classification, Corner Freedom 303 

Classification, Drop Lock 302 

Classification, Guard Freedom 304 

Club Tooth 30 

Comparisons of the Tests 379, 380, 381, 382 

Corner Freedom 79 

Corner Freedom, Analysis of 225 

Corner Freedom and Guard Freedom, Summary of (Elgin) .. .246 
Corner Freedom and Guard Freedom, Summary of (South 

Bend) 249 

Corner Freedom and Slide (Elgin) 244 

Corner Freedom and Slide (South Bend) 247 

Corner Freedom, Classification of 303 

Corner Freedom, Decreasing (Rule) 311 

Corner Freedom, Increasing (Rule) 310 

Corner, Releasing 62 

Corner, Safety Lock 218 

Corner Trip , . 87 

Corner Safety Test 80, 194 

Corner Safety Test, Findings by the 294 

Corner Safety Test, Method of Making the 292 

Corner Safety Test, Out of Angle as Shown by the 368, 369 

Corner Safety Test, Questions on the 478 

Corner Safety Test, S., and D. R., Questions on the 471 

Corner Safety Test, Single Roller 194 

Corner Safety Test, Double Roller 205 

Corner Test 78 

Corner Test Banked to Drop 239, 240 

Corner Test, Deductions from Specifications 238 

Corner Test Findings 293 

Corner Test in Practice 241, 242, 243, 412 



Corner Test, Index to Test Lessons 324 

Corner Trip 87 

Correct Escapement, The 269 

Correct Escapement, The Commercially 270 

Crescent 75, 146 

Crescent, Width of (Note) 198 

Curve Safety Lock 219 

Curve Safety Test 82, 195 

Curve Safety Test, Double Roller 206 

Curve Safety Test, Single Roller 295 

Curve Safety Test Index 370 

Curve Safety Test, Double Roller, Method of Making the 301 

Curve Safety Test, Single Roller, Method of Making the 299 

Curve Safety Test, Questions on the 472, 473, 482, 483 

Curve Test 81 

Curve Test, Double Roller 208 

Curve Test, Single Roller 197 

Curve Test, Double Roller, Method of Making the 300 

Curve Test, Single Roller, Method of Making the 298 

Curve Test, Questions on the 472, 473, 483 

Curve Trip 88 

D 

Degree 102 

Degree, Length of 104 

Degrees of Drop, Approximating 183 

Degrees of Impulse Angle, Measuring 417 

Degrees of Lever's Angular Motion, Measuring 417 

Degrees of Lift on Pallet, Measuring 417 

Degrees of Lift on Tooth, Measuring 417 

Degrees of Lock, Approximating 183 

Degrees of Lock, Calculating 180 

Degrees of Lock, Measuring 417 

Degrees of Shake, Approximating 184 A 

Degrees of Total Lock, Measuring 417 

Diamond Laps 423 

Diameter of Table 76 

Discharging Pallet 58 

Double Roller 27 

Double Roller, Corner Test 295 

Double Roller, Curve Test 208 

Double Roller, Guard Test 292 

Double Roller, Corner Safety Test 205 

Double Roller, Curve Safety Test 206 

Double Roller, Guard Safety Test 204 

Double Roller, Length of Horn in a 207 

Double Roller, Overbanking 202 

Double Roller, Questions on the Safety Actions of a 454 



Double Roller, Routine Action of a 198 

Double Roller, Roller Jewel's Safety Action in a 201 

Double Roller, Safety Action of Guard Finger 200 

Double Roller, Safety Action Parts in a 199 

Double Roller, Tripping in a 203 

Draft Angle of Pallet Jewel 114 

Draft Angle of Tooth, 126 

Drafting Circular Pallets 118 

Drafting Escape Wheel 133 

Drafting Fork 140 

Draw 23, 147 

Draw, Altering the 156 

Draw Experiments 152, 153, 154 

Draw in a Single Roller 150 

Draw in a Double Roller 151 

Draw, Its Effects 149 

Draw, Improving the 439 

Draw Lock 24 

Draw, Questions on 451 

Draw, Testing the 155, 281 

Drop , 17, 128, 157, 437, 438 

Drop, Angle of 127 

Drop, Banked to 13, 14, 15, 179 

Drop, Estimating Angle of 182, 184 

Drop, Table for Approximating Degrees of 184 

Drop, Inside 18 

Drop Inside Testing 163, 283 

Drop, Outside 19 

Drop Outside, Testing 161, 284 

Drop, Questions on 444 

Drop and Shake 17, 129 

Drop and Shake, Decreasing the 438 

Drop and Shake, Increasing the 437 

Drop and Shake, Tight Inside 165 

Drop and Shake, Tight Outside 166 

Drop and Shake When Drop Locks Are Defective 160 

Drop and Shake When Escape Wheel Is Defective 159 

Drop and Shake Rules 308, 309 

Drop Lock .38, 173 

Drop Lock, Elgin 39 

Drop Lock, South Bend 40 

Drop Lock as the Watchmaker Finds It 265 

Drop Lock, Classification of 302 

Drop Lock, Decreasing the (Rule) 309 

Drop Lock, Degrees of 180, 181 

Drop Lock in a Correct Escapement 269 

Drop Lock in a Commercial Escapement 270 

Drop Lock in a Perfect Escapement 268 



Drop Lock, Increasing the (Rule) 308 

Drop Lock, Its Relation to Banked to Drop 223 

Drop Lock, Questions on 451 

Drop Lock, Table for Approximating Degrees of 183 

Drop Lock and Corner Freedom (Rule) 320 

Drop Lock and Guard Freedom .' (Rule) 321 

Drop Lock and the Corner Test 240 

Drop Lock and the Guard Test 232 

B 

Elgin, Angular Test 254, 356, 357 

Elgin, Banked to Drop 104, (Rule) 318 

Elgin, Corner and Guard Freedom in an 226, 246 

Elgin, Comparison of Tests 379-382 

Elgin, Drop Lock in an 39, 275 

Elgin, Slide in an 42, 244 

Elgin Type of Escapement 274, 275 

Errors Shown by Angular Test 356 

Escapement 25 

Escapement Action, Routine of (Double Roller) 198 

Escapement Action, Routine of (Single Roller) 185 

Escapement Angles, Source of 210, 214 

Escapement, Double Roller 27 

Escapement, Drop Lock in an 39 

Escapement, Elgin Type of 275 

Escapement, Foreign 276 

Escapement Examination 279, 378 

Escapement Matching 267 

Escapement Out of Angle 91 

Escapement Out of Angle (Rules) 323 

Escapement, Right Angled 28 

Escapement Specifications, 216, 224, 225, 227, 230, 237, 244, 

247, 248, 251, 255 

Escapement, Straight Line 29 

Escapement, Single Roller 26 

Escapement Types and Tests Compared 379, 380, 381, 382 

Escapement, South Bend Type of 276 

Escapement Testing, Questions on 467 

Escapement, The Commercial 270 

Escapement, The Correct 269 

Escapement, The Perfect , 268 

Escapement Types 266 

Escapement, Types of American 274 

Escapement Types, Questions on 475 

Escape Wheel, Calculating Size of Lost 413 

Escape Wheel, Center, Angles Arising at 213 

Escape Wheel, Checking Size of 413 

Escape Wheel, How to Draft an 133 



vii 

Escape Wheel Specifications 132 

Escape Wheel Teeth 120 

Escape Wheel Teeth, Club 30, 131 

Escape Wheel Teeth, Ratchet 31 

F 

Pacts, Practical andTheoretical 415-422 

Foreign Escapements, Type of (Note) 276 

Fork , 51 

Fork, Angles of 138 

Fork, Angles Radiating Towards 211 

Fork, Drafting the 140 

Fork, Form of 135 

Fork Specifications 139 

Freedom, Angles of 209, 211 

Freedom, Corner 79 

Freedom, Guard 84 

Freedom, Corner and Guard (Elgin) 246 

Freedom, Corner and Guard (South Bend) 249 

Freedom, Classifying 303 

Freedom of Roller Jewel in Slot 145, 287 

G 

Guard Radius 71 

Guard Safety Lock 217 

Guard Safety Test 72, 185 

Guard Safety Test, Incorrect Findings 234, 235, 236 

Guard Safety Test, Lesson on the 351-354 

Guard Safety Test, Method of Making the 292 

Guard Safety Test, Questions on the 480 

Guard Safety Test, Double Roller 204 

Guard Safety Test, Single Roller 193 

Guard Safety Test, Single and Double Roller 289 

Guard Safety Test, Single and Double Roller, Question on the 470 

Guard Test 72, 183 

Guard Test Deductions 232 

Guard Test Findings 288 

Guard Test in Practice 233 

Guard Test, Method of Making 290, 291 

Guard Test, Out of Angle as Shown by 366 

Guard Test, Questions on the 468, 479 

Guard Test, Test Lessons on the 341-348 

Guard Test, Theory of the 229 

Guard Trip 89 

Guard and Corner Freedom Summary (Elgin) 249 

Guard and Corner Freedom Summary (South Bend) 246 

Guard Freedom 84 

Guard Freedom, Analysis of 224 



Vlll 

Guard Freedom and Slide (Elgin) 245 

Guard Freedom and Slide (South Bend) 248 

Guard Freedom, Classification of 304 

Guard Freedom, Decreasing (Rule) 313 

Guard Freedom, Increasing (Rule) 312 

Guard Finger 69 

Guard Finger, Positions of the 201 

Guard Finger, Safety Actions of the 200 

Guard Pin 68 

Guard Pin, Effect of Bending the 222 

Guard Pin, Positions of the 185 

Guard Pin, Safety Action of the 188 

Guard Pin Shaped Question Mark 442 

Guard Pin, Tool for Thinning 441 

Guard Point 70 

Guard Point, Advancing Position of the 431 

Guard Point and Table Errors, Correction of 407, 408 

Guard Point Butting Table (Rule) 319 

Guard Point Butting Table (Test Lesson) 349 

Guard Point, Question on the 460 

Guard Point When Too Close, Altering Position of 432 

H 

Heel of Tooth 35 

Hints and Helps 401-414 

Hints and Helps, Question on 484 

Horn and Roller Jewel, Separation of 220 

Horn and Roller Jewel, Relation of (Double Roller) 201 

Horn and Roller Jewel, Relation of (Single Roller) 196 

Horn, Lever 49 

Horn, Testing Length of 198 (Note), 207 

I 

Impulse and Safety Table, Questions on the 458 

Impulse Angle, Measuring Degrees of 417 

Impulse Angle of Pallet 112 

Impulse Angle of Roller Jewel 416 

Impulse Angle of Tooth 124 

Impulse Face of Pallet 59 

Impulse Face of Tooth 34 

Impulse Pin 65 

Impulse Roller 73 

Increasing Lock, Effect of 308 

Inside Drop 18 

Inside Drop, Testing the 163 

Inside Shake 20 

Inside Shake, Testing the 164, 285 

Index, Angular Test, Test Lesson's 355 



Index, Bench Problems 385 

Index, Corner and Corner Safety Test, Test Lessons 324 

Index, Curve and Curve Safety Test, Test Lessons 370 

Index, Facts, Practical and Theoretical 415 

Index, Guard and Guard Safety Test, Test Lessons 341 A 

Index, Hints and Helps 400 

Index, Out of Angle, Test Lessons 362 

Index, Rules 307 

Index to Escapement Examinations 378 



Length of Degree 104 

Let Off, Adjusting the 92 

Lever, The 47,134 

Lever, Acting Length of 48 

Lever, Horns of 49 

Lever, Increasing Entire Length of 416 

Lever, Questions on the 466 

Lever, Run of 52 

Lever, Slot or Notch 50 

Lever, Straightening a 440 

Lever's Angular Motion 416 

Lever's Acting Length, Calculating the 418, 419 

Lever's Acting Length, Decreasing the 315, 430 

Lever's Acting Length, Effect of Cutting the 221 

Lever's Acting Length, Increasing the 314, 429 

Lever's Acting Length, Testing the 250, (No. 1) 360 

Lift 168 

Lift, Correct 169 

Lift, Correcting Errors in the 171 

Lift, Incorrect 170 

Lift, Measuring Total Degrees of 417 

Lift on Pallet 60, 168 

Lift on Tooth 32, 168 

Lift on Pallet, Measuring Degrees of 417 

Lift on Tooth, Measuring Degrees of 417 

Lift on Pallet, Questions on 448 

Lift on Tooth, Question on 450 

Lifting Angle of Pallet, Changing the 427 

Lifting Errors, Correction of 171 

Line of Centers 90 

Lock 172 

Lock, Altering the 401, (Rules) 308, 309 

Lock, Angle of 115 

Lock, Approximating Degrees of 181 

Lock, Calculating Degrees of 180 

Lock, Division (Elgin) 275 

Lock, Division (South Bend) 276 



Lock, Drop 173 

Lock, Effect of Increasing 308 

Lock, Measurement of Degrees of 417 

Lock, Questions on Drop 451 

Lock, Questions on Safety 454 

Lock, Questions on Slide 452 

Lock, Questions on Total 453 

Lock, Safety or Remaining 176 

Lock, Slide 174 

Lock, Table of Degrees of 183 

Lock, Total 175 

Locks, Testing the 282 

O 

Out of Angle 91 

Out of Angle (Rule) 323 

Out of Angle as Shown by Escapement 363 

Out of Angle, Causes Producing 263 

Out of Angle, Angular Test and 262, 264, 364 

Out of Angle, Corner Test and 323, 368, 369 

Locks, The Three Safety 177, 402 

Locks, The Three Safety (Estimating) 402 

Locking Face of Pallet 61 

Locking Pace of Tooth 33 

Lost Escape Wheel, Replacing 413 

Lost Pallets, Replacing 414 

M 

Matching, Escapement 267, 272, 273 

Measuring Angles 105 

Measuring Degrees of Lift on Pallet 417 

Measuring Degrees of Lift on Tooth 417 

Measuring Degrees of Total Lift 417 

Measuring Degrees of Lock 417 

Motion of Balance 109 

Out of Angle, Guard Test and 323, 366, 367 

Out of Angle, Index to Test Lesson on 362 

Out of Angle, Questions on 481 

Out of Angle, Test Lesson on 363-369 

Out of Truth, Table 409 

Outside Drop 19 

Outside Drop, Testing 161 

Outside Shake 22 

Outside Shake, Testing 162, 286 

Overbanking 46 

Overbanking, Causes of (Single Roller) 190, 191 

Overbanking, Causes of (Double Roller) 202 



xi 

P 

Pallet 53 

Pallet Arms 54 

Pallet, Angle of Draft of 114 

Pallet, Angle of Impulse or Lift 60. 112 

Pallet, Angle of Lock of 115 

Pallet, Angle of Width of 113 

Pallet, Angles Shaping a Ill 

Pallet Center, Angles Arising at 211 

Pallet Center from Tooth's Heel, Freedom of 422 

Pallet, Entering or Receiving 57 

Pallet, Exit or Discharging 58 

Pallet, Impulse Face of 59 

Pallet Jewels 55 

Pallet Jewel, Form of a 110 

Pallet Jewel, Resetting a 403, 404, 405, 406 

Pallet, Lift on 60 

Pallet Lift, Questions on 448 

Pallet, Lifting Action on 168 

Pallet, Questions on the 447 

Pallet, Releasing Corner of 62 

Pallet, Staff 56 

Pallet Stone, Grinding Thinner 426 

Pallet Stone Setters 425 

Pallets, Circular 63,116 

Pallets, Drafting 118 

Pallets, Question on 447 

Pallets, Replacing Lost 414 

Pallets, Specifications for 119 

Perfect Escapement 268 

Pitch of Tooth 33 

Pin, Banking 11, 178 

Protractor 105, 417 

Proof Findings, Angular Test 357 

Proof Findings, Corner Test 325 

Proof Findings, Guard Test 325 

Proof Findings Contrasted 382 

Proof Findings, Test Lesson on 325 

Q 

Questions, Angular Test 466, 481 

Questions, Altering Parts 486 

Questions, Bank and Banking Pins 455 

Questions, Banked to Drop 457 

Questions, Butting Errors 479 

Questions, Corner Test 477 

Questions, Corner Test, Single and Double Roller 469 

Questions, Corner Safety Test 478 



Questions, Corner and Corner Safety Test, Single and Double 

Roller 471 

Questions, Curve and Curve Safety Test, Double Roller.. 473, 482 
Questions, Curve and Curve Safety Test, Single Roller.. 472, 483 

Questions, Draw 443 

Questions, Drop 444 

Questions, Drop Lock 451 

Questions, Escapement Types 475 

Questions, Guard Point 460 

Questions, Guard Test 479 

Questions, Guard Safety Test 480 

Questions, Guard Safety Test, Single and Double Roller 468 

Questions, Guard and Guard Safety Test, Single and Double 

Roller 470 

Questions, Hints and Helps 484 

Questions, Impulse and Safety Table 458 

Questions, Lever 446 

Questions, Lift on Pallet 448 

Questions, Lift on Tooth 450 

Questions, Out of Angle 481 

Questions, Overbanking 456 

Questions, Pallet 447 

Questions, Roller Jewel 459 

Questions, Rules and Alterations , 476 

Questions, Safety Action, Double Roller 462 

Questions, Safety Action, Single Roller 461 

Questions, Safety Lock 454 

Questions, Shake 445 

Questions, Slide 452 

Questions, Summary of Tests 467 

Questions, Tests and Escapement Testing 467 

Questions, Theory and Practice 485 

Questions, Tooth of Escape Wheel 449 

Questions, Total Lock 453 

Questions, Tripping, Double Roller 464 

Questions, Tripping, Single Roller 463 

R 

Radius 96 

Radius of Roller Jewel 66 

Receiving Pallet 57 

Releasing Corner of Pallet 61 

Remaining or Safety Lock 44 

Resetting Pallet Jewels 403, 404, 405, 406 

Resetting the Roller Jewel 411 

Right Angled Escapement 28 

Roller Jewel 65, 141 

Roller, Jewel, Action of the 142 



Xlll 

Roller Jewel, Angles Relating to the 145 

Roller Jewel and Slot Corner 433, 444 

Roller Jewel, Correct Resetting of the 411 

Roller Jewel, Fit in Slot of 287 

Roller Jewel, Impulse Angle of 416 

Roller Jewel, Questions on the 459 

Roller Jewel Radius, Calculating the 418, 419 

Roller Jewel, . Relation of Horn to 196 

Roller Jewel, Safety Action of the 189, 201 

Roller Table 144 

Roller Table, Angle of Freedom for 145 

Roller Table, Diameter of 76 

Roller Table, Questions on the 458 

Roller Table, Replacing a Lost 410 

Roller Table Too Large, Altering 435 

Roller Table Too Small, Altering 436 

Roller Table, Crescent in Edge of 75 

Rules, Index to 307 

Rule, Decreasing Corner Freedom 311 

Rule, Increasing Corner Freedom 310 

Rule, Decreasing Drop Lock 309 

Rule, Increasing Drop Lock 308 

Rule, Decreasing Guard Freedom 313 

Rule, Increasing Guard Freedom 312 

Rule, Decreasing Lever's Length 315 

Rule, Increasing Lever's Length 314 

Rule, Banked to Drop 318 

Rule, Corner Freedom and Drop Lock Defective 320 

Rule, Closing the Banking Pins 817 

Rule, Opening the Banking Pins 316 

Rule, Escapement Out of Angle 323 

Rule, Guard Freedom and Drop Lock Defective 321 

Rule, Guard Point Butting Table 319 

Rule, Protection of Safety Lock 322 

Rule, Shake and Drop 437, 438 



Safety Action 67 

Safety Action, Double and Single Roller , 187, 199 

Safety Action, Guard Fingers, Double Roller 200 

Safety Action, Guard Pins, Single Roller 188 

Safety Action, Questions on the 461, 462 

Safety Action, Remarks Concerning the 215 

Safety Action, Roller Jewel's, Double Roller 201 

Safety Action, Roller Jewel's, Single Roller 189 

Safety Lock, The Remaining or 44, 176 

Safety Lock, Protection of the 216 (Rule) 322 

Safety Lock, Questions on the 454 



xiv 

Safety Lock Relating to Guard Point and Roller 217 

Safety Lock Relating to Slot Corner and Roller Jewel 218 

Safety Lock Relating to Horn and Roller Jewel 219 

Safety Lock, Specifications 216 

Safety Lock, The Three .177, 402 

Safety Roller or Table .' 74 

Safety Test, Corner 80 

Safety Test, Corner (Double Roller) 205, 294 

Safety Test, Corner ( Single Roller 194, 294 

Safety Test, Curve 82 

Safety Test, Curve (Double Roller) 206, 301 

Safety Test, Curve (Single Roller) 195, 299 

Safety Test, Guard 72, 183 

Safety Test, Guard (Double Roller) 194, 204. 292 

Safety Test, Guard (Single Roller) 193, 196, 292 

Semi-circle 99 

Shake 20, 130 

Shake, Approximating Degrees of 184 A 

Shake, Inside 21 

Shake, Inside (Testing) 164, 285 

Shake, Outside 22 

Shake, Outside (Testing) 162, 286 

Shake, Providing 167 

Shake, Questions on l 466 

Shake and Drop, Decreasing the 438 

Shake and Drop, Increasing the 437 

Single Roller, Corner Test 78 

Single Roller, Curve Test 197 

Single Roller, Guard Test 193 

Single Roller, Corner Safety Test 194 

Single Roller, Curve Safety Test 195 

Single Roller, Guard Safety Test 185 

Single Roller Escapement 26 

Single Roller, Overbanking (Causes) 191 

Single Roller, Overbanking in a 190 

Single Roller, Questions on the Safety Action 461 

Single Roller, Roller Jewels' Relation to Horn in a 196 

Single Roller, Routine Action of a 185 

Single Roller, Safety Action in a 187 

Slide or Slide Lock 41, 174 

Slide (Elgin) 42 

Slide (South Bend) 43 

Slide and Corner Freedom (Elgin) 244 

Slide and Corner Freedom (South Bend) 247 

Slide and Guard Freedom (Elgin) 245 

Slide and Guard Freedom (South Bend) 248 

Slide, Its Relation to Draw 148 

Slide, Question on 452 



XV 

Slot 137 

Slot, Corner of 136 

Slot Corner and Roller Jewel (Apart) ) 434 

Slot Corner and Roller Jewel (Too Close) 433 

Source of Escapement Angles 210 

South Bend, Banked to Drop 227, (Rule) 318 

South Bend, Comparison of Tests in a 383, 384 

South Bend, Corner Freedom in a 228, 247 

South Bend, Drop Lock in a 276 

South Bend, Guard Freedom in a 228, 248 

South Bend, Safety Lock in a 247, 248 

South Bend Type of Escapement 274, 276 

Specifications, Deductions from 231 

Specifications, Escape Wheel 132 

Specifications, Elgin Type 216, 224, 225, 230, 237, 244, 251 

Specifications, Fork 139 

Specifications, Pallet 119 

Specifications, Safety Lock 216 

Specifications, South Bend Type 227, 247, 248, 255 

Straight Line Escapement 29 

Summary of the Tests 280 

Supplementary Arc 107 

T 

Table, Diameter of 76 

Table, Roller 73 

Table Out of Truth 409 

Table of Degrees of Drop 184 

Table of Degrees of Shake 183 

Tangent 98 

Test, Division and Summary of 280 

Test, Angular 258 

Test, Corner 295, 296 

Test, Curve 299, 300 

Test, Guard 290, 291 

Test, Out of Angle 323 

Test (Safety Test), Corner 297 

Test (Safety Test), Curve 299, 301 

Test (Safety Test), Guard 292 

Tests, Comparisons of the 379-382 

Testing Draw 281 

Testing Drop Inside and Out 283, 284 

Testing Curve of Horn 197, 208 

Testing Length of Lever Horns 198, (Note) 207, (No. 1) 356 

Testing Lock 282 

Testing Roller Jewel's Fit in Slot 287 

Total Lock 175 

Total Lock, Question on 453 



Trip, Corner 87 

Trip, Curve 88 

Trip, Guard 89 

Tripping 86 

Tripping (Double Roller) 203 

Tripping (Single Roller) 192 

Tripping, Question on 463, 464 

Types of American and Foreign Escapements 274, 276 

Tooth, Angle of Width of 125 

Tooth, Angles Radiating Towards a 123 

Tooth, Angles Shaping a 123 

Tooth, Club 30 

Tooth, Draft Angle of 122, 126 

Tooth, Heel of 35 

Tooth, Impulse Angle of 124 

Tooth, Impulse Face of 34 

Tooth, Lift on 32, 168 

Tooth, Pitch of Locking Face of 33 

Tooth, Questions on a 449 

Tooth, Ratchet 31 

Tooth, Toe of 36 

Tooth, Width of 125 

V 
Vibration, Arc of , 108 

W 

Width of Crescent (Note) 198 

Width of Pallet 113 

Width of Tooth 125 

Width of Roller Jewel. 147, 287 

Width of Slot 147 

Widths, Pallet and Tooth Division of the 421 



LIBRARY OF CONGRESS 




017 107 448 4 



ib 



